JP4926772B2 - Actuator and image projection apparatus using the actuator - Google Patents

Description

  The present invention relates to an actuator that can be used to adjust the position of an image projection apparatus such as a projector, and an image projection apparatus that uses this actuator.

  Conventionally, an image projection apparatus such as a projector has been provided with a position adjustment mechanism for adjusting the elevation angle of the image projection apparatus in order to adjust the height position of the projected image on the screen. As the most inexpensive and general position adjustment mechanism, a manual operation type that is manually operated by an operator is known, but in the case of a position adjustment mechanism that requires such manual operation, Since the operation is troublesome and fine adjustment is difficult, it takes time to set the image projection apparatus.

  Therefore, in the technical field of the position adjustment mechanism used in the image projection apparatus, various actuators have been devised that operate with a drive source such as a motor and adjust the elevation angle of the image projection apparatus by electric motor control. .

  For example, an actuator described in the following Patent Document 1 has a rack gear formed on a leg portion and a pinion gear meshing with the rack gear, and the legion protrudes by rotating the pinion gear with a motor. It is what I do.

  The actuator described in Patent Document 2 below is composed of members such as a projecting member, a worm gear, a gear, and a screw shaft. When an electric motor that is a drive source rotates, the worm gear rotates, thereby the gear and screw. The shaft rotates. When the screw shaft rotates, the projecting member moves in the axial direction of the screw shaft in accordance with the rotational direction of the screw shaft, so that the projecting member can be raised or lowered according to the rotational operation of the electric motor. ing.

JP 2003-5279 A Special table 2003-104893

  However, the conventional actuators represented by the above-mentioned Patent Documents 1 and 2 have a large apparatus shape, so that there are many restrictions when installing the image projection apparatus, and the image projection apparatus provided with the conventional actuator has its weight. Had the problem of becoming larger.

  Further, in the case of the conventional actuator, there is no force escape area when the leg portion or the protruding member is protruded and an overload is applied from the outside, so that gears for transmitting the driving force to the leg portion and the protruding member are provided. There was also a problem that it was not possible to prevent destruction.

  In addition, conventional actuators do not have a mechanism to operate the legs or protruding members when the motor that is the drive source fails or the power supply is interrupted due to some abnormality during use. There was a problem that the operation of was completely impossible.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a new actuator that realizes space saving while maintaining the stroke and thrust of a conventional actuator. It is in. Another object of the present invention is to provide a new actuator having a mechanism capable of avoiding the destruction of components even when an overload is applied from the outside with the legs protruding. It is. Furthermore, an object of the present invention is to provide a new actuator having a mechanism capable of operating a leg portion even when no power is supplied.

  An actuator according to the present invention includes a casing, a driving source that generates a rotational driving force, a worm gear that can be rotated by receiving the rotational driving force from the driving source, and a gear groove that meshes with a screw gear portion of the worm gear. An actuator having a projecting shaft that can project from the casing along with the rotation of the worm gear, wherein the drive source and the worm gear are configured as an integral member to form a drive unit. The drive unit is configured to be movable within the casing, and a stopper member that can press the drive unit is installed in the casing, so that the drive unit is always pressed against the stopper member. As a result, the meshed state between the worm gear and the protruding shaft is maintained. Wherein the meshing state between the worm gear and the protrusion shaft is released when the pressing against said drive unit of said stopper member is released.

  In the actuator according to the present invention, the drive unit includes a convex portion, the casing includes a long hole that allows the convex portion to be inserted and extends in a moving direction of the drive unit in the casing, and the long hole is The drive unit may be configured to guide movement in the casing.

  Further, in the actuator according to the present invention, the drive unit and the stopper member include a facing contact surface that faces each other, and the facing contact surface moves in the casing of the drive unit. It can form so that it may have an angle of the diagonal direction.

  Furthermore, the actuator which concerns on this invention WHEREIN: The said stopper member can make the said drive unit pressable by being pressed by the elastic body installed in the said casing.

  Still further, the actuator according to the present invention includes a leg portion that receives the projecting power from the projecting shaft, and the leg portion is pivotally attached to the casing at one end side, and the body portion is engaged with the projecting shaft. By doing so, it can be configured to be tiltable.

  Furthermore, in the actuator according to the present invention, the casing is provided with a switch device at a stroke end of the protruding shaft, and a pressing rod formed on the protruding shaft presses the switch knob of the switch device. Thus, a stop signal of the drive source can be transmitted.

  An image projection apparatus according to the present invention includes a position adjustment mechanism for adjusting an elevation angle of a projected image to be projected, and uses the actuator according to the present invention as the position adjustment mechanism. To do.

  ADVANTAGE OF THE INVENTION According to this invention, the new actuator which implement | achieved space saving can be provided, maintaining the stroke and thrust which the conventional actuator has.

  In addition, according to the present invention, it is possible to provide a new actuator having a mechanism capable of avoiding the destruction of the constituent members even if an overload is applied from the outside with the legs protruding.

  Furthermore, according to the present invention, it is possible to provide a new actuator provided with a mechanism capable of operating the legs even when no power is supplied.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. The following embodiments do not limit the invention according to each claim, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. .

  Note that the embodiment described below exemplifies a case where the actuator according to the present invention is used as a position adjustment mechanism for adjusting the elevation angle of an image projection apparatus such as a projector.

  1A and 1B are external perspective views showing the overall configuration of the actuator according to the present embodiment. In particular, FIG. 1A shows a state where the leg portion 15 is stored, and FIG. 1B shows the leg portion. The state when 15 protrudes is shown. 2A and 2B are external perspective side views when the actuator according to the present embodiment is viewed from the side. 2A shows a case where the final worm gear 26 and the protruding shaft 31 described later are kept in meshing state, and FIG. 2B shows that the meshing state of the final worm gear 26 and the protruding shaft 31 is released. Shows the case. Further, FIG. 3 is an external side view of the actuator according to the present embodiment when viewed from the side surface opposite to FIGS. 2A and 2B.

  1A to 2B, in order to describe in detail the internal configuration of the actuator according to the present embodiment, a state in which one side of the casing constituting the outer shell (a half casing positioned on the front side of the paper) is removed. It is drawn in. Of course, when the half casing on one side is actually used, it is superimposed on the other half casing drawn on the back side of the drawing sheet to form the casing.

  The actuator 10 according to the present embodiment shown in FIGS. 1A to 3 includes a casing 11 that constitutes an outline of the actuator 10. The casing 11 protects various members constituting the actuator 10 and also functions as an attachment portion when attaching to an image projection apparatus such as a projector. In the case of the casing 11 according to the present embodiment, a pair of flange portions 11a and 11a are provided at positions above the leg portion 15 serving as an action portion, and screw holes formed in the pair of flange portions 11a and 11a are provided. By using this, the actuator 10 is attached to the image projection apparatus.

  A drive unit 21 is installed inside the casing 11. Here, the drive unit according to the present embodiment will be described with reference to FIG. FIG. 4 is an external perspective side view for explaining the drive unit according to the present embodiment.

  The drive unit 21 according to the present embodiment includes a motor 22 as a drive source capable of generating a rotational drive force, a motor gear 23 installed on a motor drive shaft included in the motor 22, and a rotational drive force from the motor gear 23. The first intermediate worm gear 24 that decelerates the first intermediate worm gear 24, the second intermediate worm gear 25 that further decelerates the rotational driving force from the first intermediate worm gear 24, and the rotational driving force from the second intermediate worm gear 25 are rotatable. A final worm gear 26 and a unit case 27 for housing these members.

  In the drive unit 21, the driving force of the motor 22 is decelerated in multiple stages and is finally transmitted to the final worm gear 26, and rotational power can be transmitted to the outside via the final worm gear 26. Each of the three worm gears 24, 25, and 26 has a cylindrical portion and a disk portion connected to the cylindrical portion. In the three worm gears 24, 25, and 26, screw gear portions 24 a, 25 a, and 26 a are formed by cutting spiral and continuous teeth with respect to the cylindrical portion, and with respect to the outer peripheral side surface of the disk portion. Helical gear portions 24b, 25b, and 26b are formed by cutting arc-shaped teeth corresponding to the screw gear portions 24a, 25a, and 26a. These worm gears 24, 25, and 26 have a self-stopping property so that they only perform forward rotation, and also have the advantage that a very high reduction ratio can be obtained in a compact manner. Yes.

  In the drive unit 21 of the present embodiment, a gear system using three worm gears 24, 25, and 26 is constructed. However, these configurations are the specifications and installation conditions of the image projection apparatus in which the actuator 10 is installed. The drive unit of the present invention includes a drive source that generates a rotational drive force and at least one worm gear that can rotate by receiving the rotational drive force from the drive source. What is necessary is just to have the structure provided.

  Furthermore, the drive unit 21 of the present embodiment is configured to be movable in the lateral direction (the left-right direction in FIG. 2A, FIG. 2B, and FIG. 3) within the casing 11. Although the reason why it is configured to be movable will be described in detail later, the movement mechanism will be described with reference to FIG. 3. When the side of the casing 11 is provided, a motor opening 11 b for penetrating the motor 22, A long hole 11c extending in the lateral direction is formed above the opening 11b. This long hole 11c is for penetrating the convex portion 27c included in the drive unit 21, and is formed so that a gap S1 is formed in the lateral direction with respect to the shape of the convex portion 27c. Further, the motor opening 11 b is also formed so that a gap S <b> 2 is left in the lateral direction with respect to the outer shape of the motor 22. Therefore, the drive unit 21 can move by the lateral gaps S1 and S2 of the motor opening 11b and the long hole 11c. That is, when the drive unit 21 moves in the lateral direction, the movement of the motor 22 and the convex portion 27c is stably guided by the motor opening 11b and the long hole 11c.

  Inside the casing 11, a protruding shaft 31 is further installed on the front side of the drive unit 21 (the right side in FIG. 2A and FIG. 2B). The protruding shaft 31 will be described with reference to FIG. 5. The protruding shaft 31 includes a gear groove 31 a that meshes with the screw gear portion 26 a of the final worm gear 26, and the lower side of the casing 11 as the final worm gear 26 rotates. Can protrude freely.

  Two strips 31 b extending in the vertical direction are formed on the side surface of the projecting shaft 31, and the two strips 31 b are fitted with two projections (not shown) formed inside the casing 11. This realizes a stable guide movement when protruding downward.

  The protruding shaft 31 is formed with a single pressing rod 31c. The pressing bar 31 c is a member for pressing the switch knob of the switch device 32 installed in the casing 11. That is, the casing 11 is provided with two switch devices 32, 32 at the upper and lower positions that are the stroke ends of the projecting shaft 31, and the pressing rod 31 c formed on the projecting shaft 31 is connected to the switch devices 32, 32. A stop signal of the motor 22 can be transmitted by pressing the switch knob. By installing such a safety device, the protruding shaft 31 does not protrude too much or is stored too much.

  Further, two engaging shafts 31 d protruding in the lateral direction are formed on the lower end side of the protruding shaft 31. The engagement shaft 31d is a member that engages with an engagement groove 15a formed in a body portion of the leg portion 15 serving as an action portion of the actuator, and applies a vertically downward projecting power to the leg portion 15. Can be done. In addition, since one end side of the leg portion 15 is pivotally attached to the casing 11, the leg portion 15 can be tilted around the pivot point of the casing 11 by receiving the projection power from the projection shaft 31. Therefore, the elevation angle of the projection image projected from the image projection device can be adjusted by controlling the tilting amount of the leg portion 15 (that is, the protruding amount of the protruding shaft 31).

  Furthermore, a stopper member 35 capable of pressing the drive unit 21 is installed inside the casing 11 on the rear side of the drive unit 21 (the left side in FIG. 2A and FIG. 2B). The stopper member 35 will be described with reference to FIG. FIG. 6 is an external perspective view showing the stopper member according to this embodiment.

  The stopper member 35 shown in FIG. 6 always receives a pressing force from the upper side toward the lower side by an elastic body 36 such as a spring installed in the casing 11. The stopper member 35 has an operation handle 35c on the lower end side. The operation handle 35c is a member configured to protrude downward from the casing 11, and when the operator pushes the operation handle 35c upward against the elastic force of the elastic body 36, the entire stopper member 35 is moved. It can be moved upward. Since the upward movement stroke of the stopper member 35 is defined by the fluctuation range of the elastic body 36, it is preferable to determine the length of the operation handle 35c according to this fluctuation range.

  Furthermore, the stopper member 35 has two opposing contact surfaces 35 a and 35 b that come into contact with the drive unit 21, and the two opposing contact surfaces 35 a and 35 b have a surface direction within the casing 11 of the drive unit 21. It is formed so as to have an oblique angle with respect to the moving direction at. On the other hand, the drive unit 21 is also provided with two opposing contact surfaces 27a and 27b that come into contact with the two opposing contact surfaces 35a and 35b of the stopper member 35, respectively. Also, the surface direction is formed so as to have an oblique angle with respect to the moving direction of the drive unit 21 in the casing 11.

  Since the stopper member 35 has the above-described configuration, in the normal state, the stopper member 35 is pressed downward by the elastic body 36 and is formed to have an angle in the oblique direction, particularly at the upper side. By the action of the contact surfaces 27a and 35a, the drive unit 21 is pressed forward (the right side in FIG. 2A and FIG. 2B). When the drive unit 21 moves to the front side (the right side in FIG. 2A and FIG. 2B), the final worm gear 26 provided in the drive unit 21 and the gear groove 31a of the projecting shaft 31 are maintained in meshing state. The driving force 22 can be transmitted to the leg 15 (the state shown in FIG. 2A).

  On the other hand, when the stopper member 35 is lifted upward against the elastic force of the elastic body 36, the drive unit 21 is caused by the action of the lower opposing contact surfaces 27 b and 35 b formed to have an oblique angle. Is pushed rearward (the left side in FIG. 2A and FIG. 2B). When the drive unit 21 moves to the rear side (the left side in FIG. 2A and FIG. 2B), the meshing state between the final worm gear 26 provided in the drive unit 21 and the gear groove 31a of the protruding shaft 31 is released. The leg portion 15 is in a free state (the state shown in FIG. 2B).

  The meshing state of the final worm gear 26 provided in the drive unit 21 and the gear groove 31a of the projecting shaft 31 can be changed without operating the stopper member 35. For example, when an overload is applied to the leg portion 15 in the direction in which the leg portion 15 is accommodated when the leg portion 15 is in a state of protruding downward (shown in FIG. 1B), the gear groove 31a of the protruding shaft 31 is applied. And the force which presses the drive unit 21 to the back side (paper surface left side in FIG. 2A and 2B) acts via the last worm gear 26. FIG. The drive unit 21 can move to the rear side (left side in FIG. 2A and FIG. 2B) while lifting the stopper member 35 upward by the action of the upper facing contact surfaces 27a and 35a. By providing such a configuration, the actuator 10 according to the present embodiment can prevent the destruction of the members of the drive system such as the protruding shaft 31 and the final worm gear 26 even if an overload is applied from the outside. It has become.

  Heretofore, the overall configuration and the constituent members of the actuator according to the present embodiment have been described. Next, the operation of the actuator according to this embodiment will be described.

  The operation of the motor 22 is executed by turning on the power of a drive source (not shown). The rotational driving force of the motor 22 is transmitted to the final worm gear 26 via the motor gear 23, the first intermediate worm gear 24, and the second intermediate worm gear 25. Since the final worm gear 26 is always meshed with the gear groove 31 a of the protruding shaft 31 by the action of the stopper member 35, the rotational driving force of the final worm gear 26 is converted into the protruding power for the protruding shaft 31. Will project downward. Since the projecting shaft 31 is formed with two engaging shafts 31d that engage with the engaging grooves 15a formed in the body portion of the leg portion 15, the projecting power of the projecting shaft 31 is increased by the two engaging shafts 31d. Is transmitted to the leg portion 15 through the movement, and the tilting operation of the leg portion 15 is realized with the axis of contact with the casing 11 as the center of tilting.

  The tilting amount of the leg portion 15 can be adjusted by controlling the rotational driving amount of the motor 22. Further, since the final worm gear 26 does not reversely rotate due to its self-stopping property, the fixed state of the leg portion 15 when the motor 22 is stopped is maintained.

  However, when an overload is applied from the outside to the leg portion 15 in the projecting state, the final worm gear 26 is pushed through the projecting shaft 31, so that the entire drive unit 21 is overloaded. It will be. In such a case, the drive unit 21 can move to the rear side (the left side in FIG. 2A and FIG. 2B) against the pressing force of the stopper member 35, so that the components such as the worm gears 24, 25, and 26 are destroyed. Can be prevented. As described above, the movement of the drive unit 21 due to the load from the leg portion 15 side is realized particularly by the action of the opposed contact surfaces 27 a and 35 a on the upper side of the drive unit 21 and the stopper member 35.

  Further, when the motor 22 cannot be rotated due to a power failure or the like, the leg member 15 can be tilted by operating the stopper member 35. That is, as shown in FIG. 2B, when the stopper member 35 is moved upward, the drive unit 21 is moved to the rear side (FIG. 2B) by the action of the opposed contact surfaces 27b and 35b on the lower side of the drive unit 21 and the stopper member 35. Therefore, the meshing state between the final worm gear 26 and the gear groove 31a of the protruding shaft 31 is released. In this case, since the leg portion 15 is in a free state, if the stopper member 35 is released after the leg portion 15 is moved to a desired position, the leg portion 15 can be fixed at the desired position.

  As mentioned above, although preferred embodiment of this invention was described, the technical scope of this invention is not limited to the range as described in the said embodiment. Various modifications or improvements can be added to the embodiment. That is, in the actuator according to the present embodiment, the case where the actuator is used as the position adjustment mechanism for adjusting the elevation angle of the projection image projected from the image projection apparatus has been described. However, the actuator according to the present invention is used for such applications. It is not limited. For example, it can be used as an actuator for devices that perform tilt operations in various fields such as medical devices, semiconductor manufacturing devices, precision devices, various measuring instruments, and portable devices.

  In the above-described embodiment, the case where the leg portion 15 is positioned downward and the image projection apparatus is tilted upward has been described. However, the actuator according to the present invention can be used in any direction and any posture.

  Furthermore, it is possible to omit the leg portion 15 described in the present embodiment and use the protruding shaft 31 as the action portion. When this configuration is adopted, the tilt range of the image projection apparatus is narrower than that in the above-described embodiment, but there is an advantage that the number of parts can be reduced and the cost can be reduced. It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

FIG. 2 is an external perspective view showing the overall configuration of the actuator according to the present embodiment, and particularly shows a state in which the legs are stored. FIG. 2 is an external perspective view showing the overall configuration of the actuator according to the present embodiment, and particularly shows a state where the leg portion protrudes. FIG. 3 is an external perspective side view when the actuator according to the present embodiment is viewed from the side, and particularly shows a case where the final worm gear and the projecting shaft maintain the meshing state. FIG. 3 is an external perspective side view when the actuator according to the present embodiment is viewed from the side, and particularly shows a case where the meshing state between the final worm gear and the protruding shaft is released. It is an external appearance side view at the time of seeing the actuator which concerns on this embodiment from the side surface on the opposite side to FIG. 2A and 2B. It is an external see-through | perspective side view for demonstrating the drive unit which concerns on this embodiment. It is an external appearance perspective view which shows the protrusion shaft which concerns on this embodiment. It is an external appearance perspective view which shows the stopper member which concerns on this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Actuator, 11 Casing, 11a Flange part, 11b Motor opening part, 11c Long hole, 15 Leg part, 15a Engagement groove, 21 Drive unit, 22 Motor, 23 Motor gear, 24 First intermediate worm gear, 25 Second intermediate worm gear 26 Final worm gear, 24a, 25a, 26a Screw gear part, 24b, 25b, 26b Helical gear part, 27 Unit case, 27a, 27b Opposing contact surface, 27c Convex part, 31 Projection shaft, 31a Gear groove, 31b Groove, 31c Press rod, 31d Engagement shaft, 32 Switch device, 35 Stopper member, 35a, 35b Opposing contact surface, 35c Operation handle, 36 Elastic body, S1, S2 gap.

Claims (7)

A casing,
A drive source that generates rotational driving force;
A worm gear that is rotatable by receiving a rotational driving force from the driving source;
A projecting shaft that can be freely projected from the casing as the worm gear rotates by providing a gear groove that meshes with the screw gear portion of the worm gear;
An actuator comprising:
The drive source and the worm gear are configured as an integral member to form a drive unit,
The drive unit is configured to be movable within the casing;
By installing a stopper member capable of pressing the drive unit in the casing,
The engagement state between the worm gear and the protruding shaft is always maintained by pressing the drive unit against the stopper member, and when the pressing of the stopper member against the drive unit is released, the worm gear and the protruding shaft The actuator is released from the meshing state. The actuator according to claim 1, wherein
The drive unit includes a convex portion,
The casing includes an elongated hole into which the convex portion can be inserted and extends in the moving direction of the drive unit in the casing.
The actuator, wherein the elongated hole guides the movement of the drive unit in the casing. The actuator according to claim 1 or 2,
The drive unit and the stopper member are provided with opposing contact surfaces that face each other,
The actuator is characterized in that the opposing contact surface is formed so as to have an oblique angle with respect to the moving direction of the drive unit in the casing. The actuator according to any one of claims 1 to 3,
The actuator, wherein the stopper member can press the drive unit by being pressed by an elastic body installed in the casing. The actuator according to any one of claims 1 to 4,
A leg portion for receiving the projecting power from the projecting shaft;
The leg is configured to be tiltable by having one end side pivotally attached to the casing and a body part engaging with the protruding shaft. The actuator according to any one of claims 1 to 5,
The casing is provided with a switch device at a stroke end of the protruding shaft,
An actuator characterized in that a stop signal of the drive source is transmitted by a pressing rod formed on the protruding shaft pressing a switch knob of the switch device. An image projection apparatus including a position adjustment mechanism for adjusting an elevation angle of a projected image to be projected,
An image projection apparatus using the actuator according to any one of claims 1 to 6 as the position adjustment mechanism.

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