JP2003039503A - Drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the damage to a ball screw part by absorbing an impact by a cushioning device even in a case receiving the impact and to also prevent the scattering of a lubricant by arranging a shield member around the ball screw part. SOLUTION: The drive device has a drive source equipped with a hollow rotary shaft 33 and attached to an attaching member at one side end thereof, the screw shaft locked with the inner periphery of the hollow rotary shaft 33 and arranged in the hollow rotary shaft 33 to freely advance and retreat and protruded toward the attaching member, the nut threaded with the screw shaft, a nut support member making the nut impossible to rotate and supporting the impact in an axial direction received by the nut so as to be able to buffer the same, a shield member for shielding the periphery of the nut and a member to be driven arranged to the side end on the side of the attaching member of the screw shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device.

[0002]

2. Description of the Related Art Conventionally, in a molding machine such as an injection molding machine, a resin heated and melted in a heating cylinder is injected at a high pressure to fill a cavity space of a mold device. The molded product is molded by cooling and solidifying the resin in the cavity space.

To this end, the mold device is composed of a fixed mold and a movable mold, and the mold clamping device moves the movable mold forward and backward to bring the movable mold into and out of contact with the fixed mold to open and close the mold. , Mold closing, mold clamping and mold opening can be performed.

The mold clamping device is provided with a toggle mechanism for advancing and retracting the movable mold, and the toggle mechanism drives an electric motor, a servomotor or the like provided as a drive device. Operated. Further, the movable platen of the mold clamping device is provided with a drive device for an ejector rod that projects an ejector pin for ejecting a molded product by protruding into a cavity inside the movable mold of the mold device.

FIG. 2 is a sectional view of a conventional driving device.

In the figure, 70 is a servo motor as a driving means, and the servo motor 70 is the stator 7.
1, a hollow rotary shaft 73 rotatably attached to the housing of the servomotor 70 via a bearing 74, and a rotor 72 attached to the hollow rotary shaft 73. The housing of the servomotor 70 is a plate 9
1 is attached to the movable platen 98. A flange of a female spline hollow shaft 87 inserted into the hollow rotary shaft 73 is attached to the rear end (the left end in the figure) of the hollow rotary shaft 73. An encoder 76 for detecting the rotation of the hollow rotary shaft 73 is attached to the flange via an encoder shaft 75.

The female spline hollow shaft 87 is
A spline extending in the axial direction is formed on the inner circumference, and the spline extending in the axial direction is coupled to the male spline portion 88 of the ball screw shaft 89 formed on the outer circumference.
The female spline hollow shaft 87 and the male spline portion 88
Can be moved relative to each other in the axial direction because the splines are coupled by engaging with each other, but the rotation of the female spline shaft 87 is transmitted to the ball screw shaft 89. Further, a screw is formed on the outer peripheral portion of the ball screw shaft 89 in front of the male spline portion 88.

A ball screw nut 90 mounted on a plate 91 is screwed onto the ball screw shaft 89. A movable housing 93 that is slidable along a guide bar 96 is attached to the front end of the ball screw shaft 89 via a bearing 92. The front end of the ball screw shaft 89 is attached to the bearing 9 by a nut 97.
It is fixed to the inner peripheral part of 2. A movable block 94 is attached to the movable housing 93, and further,
An ejector rod 95 that moves an ejector pin (not shown) for ejecting a molded product is attached to a central portion of the movable block 94 so as to project into a cavity inside the movable mold of the mold device.

Therefore, when the servomotor 70 is operated, the rotation of the hollow rotary shaft 73 is transmitted to the ball screw shaft 89, so that the ball screw shaft 89 screwed into the ball screw nut 90 attached to the plate 91. While rotating itself, it moves in the axial direction. Therefore, the ejector rod 95 attached to the movable housing 93 is moved forward or backward via the movable block 94. Since the movable housing 93 is attached to the ball screw shaft 89 via the bearing 92, the ball screw shaft 89
Is not transmitted to the movable housing 93 and the ejector rod 95.

In this case, since the distance from the rear end of the servomotor 70 to the ejector rod 95 is shortened, the length of the entire driving device can be shortened and the entire driving device can be miniaturized.

[0011]

However, in the above-mentioned conventional driving device, the ball screw shaft 89 or the ball screw shaft 89 is generated by the impact received when the ejector pin projects into the cavity inside the movable mold of the mold device and collides with the molded product. The ball screw nut 90 may be damaged.

Usually, a servo motor 70 as a driving means
In the case of the drive device using the above, the driving force of the servomotor 70 is relaxed immediately before the ejector pin collides with the molded product, and the ejector pin is advanced by inertia to collide with the molded product. However, the moving distance (projection amount) of the ejector pin is the same as when changing the mold device.
Is changed, the ejector pin may collide with the molded product before the driving force of the servo motor 70 is loosened. In this case, the ejector pin receives an unexpected impact, and the unexpected impact is transmitted through the ejector rod 95 to the ball screw portion including the ball screw shaft 89 and the ball screw nut 90, and the ball screw portion is damaged. It may end up.

Therefore, by supporting the ball screw nut 90 via a cushioning member such as a spring, a drive device is provided in which the ball screw portion is not damaged even if the ejector pin receives an unexpected impact. There is.

FIG. 3 is a sectional view of another conventional driving device.

In this case, the ball screw nut 90 is attached to the spring holder 65 having a spring guide insertion hole. And, a rod-shaped spring guide 6 having a large-diameter crown portion
6 is inserted into the spring guide insertion hole from the right in the drawing, the base portion (the left end in the drawing) is fixed to the plate 91, and the crown portion (the right end in the drawing) having a diameter larger than that of the spring guide insertion hole is the spring holder. It is locked to 65.

Further, the plate 91 and the spring holder 6
A spring member 67 is provided between the spring member 67 and the spring 5. Here, the spring member 67 has, for example, a central hole such as a coil spring, a spring washer, and a rubber bush, and it is desirable that the spring holder 65 be inserted into the central hole. Further, the spring holder 65 is
It is a bolt having a screw formed on the base, and is preferably screwed to the plate 91. In this case, the amount of preload applied to the spring member 67, that is, the amount of preload can be adjusted by adjusting the tightening amount of the spring holder 65 with respect to the plate 91.

In the figure, the spring guide 66 is shown.
Also, although only one spring member 67 is shown, it is actually desirable to have a plurality.

Here, in the drive unit, since the spring member 67 is preloaded, the spring holder 65 is
It is pressed against the spring guide 66 from the left side in the figure,
It cannot be moved. Therefore, the ball screw nut 90 attached to the spring holder 65 also does not move in the axial direction of the ball screw shaft 89. Therefore, like the drive device shown in FIG.
When 0 is operated, the rotation of the hollow rotary shaft 73 is transmitted to the ball screw shaft 89, so that the ball screw shaft 89 itself screwed into the ball screw nut 90 moves in the axial direction while rotating. Therefore, the ejector rod 95 attached to the movable housing 93 is moved forward or backward via the movable block 94. Thereby, the ejector pin (not shown) can be projected into the cavity inside the movable mold of the mold device to eject the molded product.

When the ejector pin receives a force to the left in the figure, the force is applied to the ejector rod 9
5, transmitted to the spring member 67 through the ball screw shaft 89 and the ball screw nut 90. Here, when the force is equal to or more than the preload applied to the spring member 67, the spring member 67
Is compressed, the spring holder 65 moves to the left in the figure. Therefore, even if the ejector pin receives an unexpectedly strong impact, the impact is absorbed by the spring member 67, so that the ball screw portion is not damaged.

However, in the conventional drive device shown in FIG. 3, since the plate 91 and the spring holder 65 are spaced apart from each other, the grease adhered to the bearing 74 of the servomotor 70, the ball screw shaft 89, etc. Such a lubricant is scattered outside between the plate 91 and the spring holder 65. In this case, the scattered lubricant contaminates the surroundings.

The present invention solves the problems of the above-mentioned conventional drive device, so that even when an impact is received, the impact is absorbed by the shock absorber so that the ball screw portion is not damaged and the shielding ( It is an object of the present invention to provide a drive device capable of preventing the lubricant from scattering by disposing a flat member around the ball screw portion.

[0022]

To this end, in a drive device of the present invention, a drive source having a hollow rotary shaft, one end of which is attached to a mounting member, and an inner peripheral surface of the hollow rotary shaft are engaged. Then, a screw shaft that is disposed in the hollow rotating shaft so as to be able to move back and forth and that protrudes toward the mounting member side, a nut that is screwed into the screw shaft, the nut that cannot rotate, and the nut A nut support member that supports the received axial shock so as to be bufferable, and a shield member that shields the periphery of the nut,
And a driven member disposed at a side end of the screw shaft on the mounting member side.

In another driving device of the present invention, the driven member drives an ejector pin projecting inside the mold.

In yet another drive device of the present invention, the nut support member is further mounted via a shock absorber so as to be movable in the axial direction of the mounting member.

In yet another drive of the invention, the shock absorber further comprises a preloaded spring element.

In still another driving device of the present invention, the shielding member is a cylindrical member attached to the nut supporting member, and movably engages with a hole formed in the attaching member.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the drive device of the present invention can be applied to various devices and applications, but in the present embodiment, for convenience of explanation, a case where it is applied to an injection molding machine will be described.

FIG. 4 is a schematic view of the mold clamping device of the injection molding machine according to the embodiment of the present invention.

In the figure, 15 is a frame, 13 is a fixed platen fixed to the frame 15, and 23 is movably arranged with respect to the frame 15 with a predetermined distance from the fixed platen 13. Toggle support as a base plate, 14 is a tie bar installed between the fixed platen 13 and the toggle support 23, 12 is arranged to face the fixed platen 13, and moves back and forth along the tie bar 14 (FIG. The movable platen is arranged so as to be movable in the left-right direction). Then, a fixed mold (not shown) is attached to a surface of the fixed platen 13 facing the movable platen 12, and a movable mold (not shown) is attached to a surface of the movable platen 12 facing the fixed platen 13.

A drive unit 10 is attached to the rear end (left end in the figure) of the movable platen 12. The drive device 10 has a motor 11 as a drive source and moves an ejector rod 24 as a driven member forward or backward (moves rightward or leftward in the drawing). Then, when the ejector rod 24 advances or retracts, an ejector pin (not shown) for ejecting a molded product by protruding into a cavity inside the movable mold in the mold device is advanced or retracted. Here, the motor 11 may be any type of motor, but is preferably a servo motor.

A toggle mechanism 18 is attached between the movable platen 12 and the toggle support 23,
At the rear end (left end in the figure) of the toggle support 23, a drive unit 10 'serving as a drive unit for clamping the injection molding machine.
Is attached. The drive device 10 ′ has a motor 11 ′ as a drive source, and can move the crosshead 17 as a driven member forward and backward to operate the toggle mechanism 18. As a result, the movable platen 12 is moved forward (moved in the right direction in the drawing) to close the mold, and a propulsive force by the motor 11 'is multiplied by a toggle magnification to generate a mold clamping force. The mold is clamped by force. In the present embodiment, the mold clamping force is generated by operating the toggle mechanism 18, but without using the toggle mechanism 18,
It is also possible to transmit the propulsive force of the motor 11 'as it is to the movable platen 12 as a mold clamping force.

The toggle mechanism 18 includes a toggle lever 21, which is swingably supported by the crosshead 17,
A toggle lever 22 swingably supported by the toggle support 23 and a toggle arm 16 swingably supported by the movable platen 12 are provided between the toggle lever 21 and the toggle lever 22. , And the toggle lever 22 and the toggle arm 16 are linked to each other.

Next, the drive unit 10 will be described.

FIG. 1 is a sectional view of a drive unit attached to a movable platen according to an embodiment of the present invention.

In the figure, a motor 11 as a drive source
Has a hollow rotating shaft 33 as a first hollow rotating shaft rotatably attached to the housing of the motor 11 via a stator 31 and a bearing 34, and a rotor 32 attached to the hollow rotating shaft 33. The front end (right end in the figure) of the housing of the motor 11 is attached to the movable platen 12 via a plate 43 as an attachment member. Here, a hole through which a ball screw shaft 41 and a ball screw nut 42, which will be described later, pass is formed in the central portion of the plate 43.

At the rear end (the left end in the figure) of the hollow rotary shaft 33, a female spline hollow shaft 37 as a second hollow rotary shaft inserted into the hollow rotary shaft 33.
The flange of is attached. Further, on the flange of the female spline hollow shaft 37, via the encoder shaft 35,
An encoder 36 as a rotation detecting means for detecting the rotation of the hollow rotary shaft 33 is attached.

Here, the female spline hollow shaft 37 is
It has a shape in which a cylindrical portion shorter than the hollow rotating shaft 33 is attached, with both ends open on one surface of a donut-shaped flange portion having a hole in the center. A spline extending in the axial direction is formed on the inner surface of the cylindrical portion. Then, a ball screw shaft 41 as a screw shaft having a male spline portion 38 in which a spline extending in the axial direction is formed on the outer periphery of the rear end portion is inserted into the female spline hollow shaft 37, and the female spline is inserted. The male spline portion 38 is engaged with the hollow shaft 37.

Since the female spline hollow shaft 37 and the male spline portion 38 are engaged with each other by the interlocking splines, they are axially movable with respect to each other.
The rotation of the female spline hollow shaft 37 is transmitted to the male spline portion 38. As a result, the rotation of the female spline hollow shaft 37 is transmitted to the ball screw shaft 41. Here, a screw is formed in a portion in front of the male spline portion 38 on the outer periphery of the ball screw shaft 41. The outer diameter of the portion where the screw is formed is the same as the female spline hollow shaft 37.
Is smaller than the inner diameter of the large-diameter part.

A ball screw nut 42 as a nut supported by a spring holder 53 as a nut supporting member is screwed into a portion of the ball screw shaft 41 protruding from the front end of the housing of the motor 11. here,
The spring holder 53 has a flange portion 5 having a hole at the center.
3a has a shape in which a short cylindrical portion 53b as a cylindrical member having open ends is attached to the back surface (left side surface in the figure). A spring guide insertion hole is formed in the flange portion 53a, and a rod-shaped spring guide 51 having a large-diameter crown portion is inserted into the spring guide insertion hole from the right side in the drawing. Base of the spring guide 51 (left end in the figure)
Is fixed to the front surface (right side surface in the figure) of the plate 43, and the crown portion 5 having a diameter larger than that of the spring guide insertion hole.
1a (right end in the drawing) is locked to the front surface (right side surface in the drawing) of the flange portion 53a.

Further, a spring member 52 is arranged between the front surface of the plate 43 and the rear surface of the flange portion 53a of the spring holder 53. The spring member 52 has a central hole such as a coil spring, a spring washer, and a rubber bush, and the spring guide 51 is preferably inserted into the central hole. Further, the spring guide 51 is a bolt having a screw formed on the base thereof, and is preferably screwed to the front surface of the plate 43. In this case, by adjusting the tightening amount of the spring guide 51 with respect to the front surface of the plate 43, the preload applied to the spring member 52, that is,
The amount of preload can be adjusted.

As described above, by the plate 43, the spring guide 51, the spring member 52 and the flange portion 53a,
A cushioning device is configured to cushion the axial impact of the ball screw nut 42 as a nut. It should be noted that although only one shock absorber is shown in the figure, it is preferable that there be a plurality of shock absorbers.

The cylindrical portion 53b of the spring holder 53
The outer diameter of is substantially equal to the inner diameter of the hole formed in the central portion of the plate 43, and the outer circumference of the cylindrical portion 53b slides along the inner circumference of the hole in the lateral direction in the figure. That is, the cylindrical portion 53b as the cylindrical member movably engages with the hole formed in the plate 43 as the mounting member.

A short cylindrical portion 43b may be formed in the hole formed in the central portion of the plate 43 as shown in the figure. As a result, the amount of overlap between the outer circumference of the cylindrical portion 53b of the spring holder 53 and the inner circumference of the hole formed in the central portion of the plate 43 can be maintained. However, when the sliding amount of the spring holder 53 is small or when the plate 43 has a large thickness, it is not necessary to form the cylindrical portion 43b.

With this structure, the cylindrical portion 53b is formed.
Functions as a shielding member that shields the ball screw portion. Further, a groove may be formed on the outer circumference of the cylindrical portion 53b of the spring holder 53 or the inner circumference of the hole formed in the central portion of the plate 43, and a seal member 54 such as an O-ring may be housed in the groove. desirable. This improves the shielding property of the shielding member.

At the front end of the ball screw shaft 41,
A movable housing 44 slidable along the guide bar 46 is attached via a bearing 45. The rear end portion of the guide bar 46 is attached to the plate 43, but the front end portion may be attached to the movable platen 12.

The front end of the ball screw shaft 41 is fixed to the inner peripheral portion of the bearing 45 by the nut 48. Thereby, the ball screw shaft 41 and the movable housing 44 are
And are rotatable relative to each other, but axially immovably coupled to each other. Since the movable housing 44 is prevented from rotating by the guide bar 46, only the forward and backward movement of the ball screw shaft 41, that is, only the linear movement in the axial direction is transmitted to the movable housing 44.

Further, a movable block 47 is attached to the movable housing 44, and an ejector rod 24 is attached to the central portion of the movable block 47. Here, the movable housing 44, the movable block 47, and the ejector rod 24 constitute a driven member. An ejector pin (not shown) is connected to the tip of the ejector rod 24 so as to project into the cavity inside the movable mold of the mold device to eject the molded product.

Next, the operation of the driving device having the above construction will be described.

First, when current is supplied to the coil of the stator 31 to drive the motor 11, the rotor 32 rotates and the hollow rotary shaft 33 attached to the rotor 32 rotates. Then, the rotation is transmitted to the encoder 36 via the encoder shaft 35 attached to the rear end of the hollow rotary shaft 33. Thereby, the rotation of the hollow rotary shaft 33 is detected.

On the other hand, the rotation of the hollow rotary shaft 33 is transmitted to the female spline hollow shaft 37 by a flange attached to the front end of the hollow rotary shaft 33. The rotation of the female spline hollow shaft 37 is caused by the male spline portion 38 which is connected to the small diameter portion by the spline.
It is transmitted to the ball screw shaft 41.

Here, the ball screw shaft 41 is screwed into the ball screw nut 42, and the ball screw nut 4
2 is attached to the spring holder 53. The spring holder 53 is prevented from rotating by a spring guide 51.
Further, since the spring member 52 is preloaded, the front surface of the flange portion 53a of the spring holder 53 is pressed against the crown portion 51a of the spring guide 51 from the left side in the drawing and moves in the axial direction of the ball screw shaft 41. There is no.
Therefore, the ball screw nut 42 cannot rotate and cannot move in the axial direction of the ball screw shaft 41. Therefore, the ball screw shaft 41 itself moves in the axial direction by rotating, that is, moves forward or backward. It should be noted that whether to move forward or backward is determined by the direction of the screw and the rotation direction of the ball screw shaft 41, but in the state shown in FIG. 1, the ball screw shaft 41 is located at the rearmost end and further retracts. Therefore, the case of moving forward will be described here.

When the ball screw shaft 41 moves forward,
The movable housing 44, the movable block 47 attached to the movable housing 44, and the ejector rod 24 attached to the movable block 47 advance. The ball screw shaft 41 and the movable housing 44 are rotatable with respect to each other, but are axially immovably coupled to each other, and the movable housing 44 is prevented from rotating by the guide bar 46. Screw shaft 41
Rotation of the movable housing 44, which is a driven member,
It is not transmitted to the movable block 47 and the ejector rod 24.

As a result, the ejector pin (not shown) moves forward and projects into the cavity inside the movable mold of the mold device to eject the molded product.

Here, when the ejector pin projects into the cavity to eject the molded product, the ejector pin receives a shock as a reaction force from the molded product. Then, the impact is transmitted to the ball screw nut 42 attached to the spring holder 53 via the ejector rod 24, the movable block 47, the movable housing 44, the bearing 45 and the ball screw shaft 41. In this case, the spring member 52
Preload is applied to the flange portion 53a of the spring holder 53.
Is pressed against the crown 51a of the spring guide 51 from the left in the figure. Therefore, even if the impact is applied, the spring holder 53 does not move in the axial direction of the ball screw shaft 41.

However, when the impact as a reaction force that the ejector pin receives from the molded product is large, that is, when the impact is larger than that expected at the time of designing, the spring member 52 has a preload or more. Receiving power,
It will be compressed. Then, the spring holder 53 moves to the left in the figure, and the ball screw nut 42 attached to the spring holder 53 also moves to the left. As a result, the impact is absorbed by the spring member 52, so that the ball screw portion including the ball screw shaft 41 and the ball screw nut 42 is not damaged.

A lubricant such as grease is supplied to the ball screw portion and the like for lubrication, but when the ball screw shaft 41 rotates, the ball screw shaft 41 is rotated by centrifugal force.
Lubricant adhering to the surface is splashed in the radial direction. However, in the present embodiment, the cylindrical portion 53b of the spring holder 53 is
Since it functions as a shielding member that shields the ball screw portion, the lubricant splashed in the radial direction does not scatter around the drive device and contaminate the periphery of the drive device.

As described above, in this embodiment, the spring guide 51 to which the ball screw nut 42 is attached is attached.
Is movably attached in the axial direction of the ball screw shaft 41 by a shock absorber including a spring member 52, and
It also functions as a shielding member that shields the ball screw portion.

Therefore, when the ejector pin receives a large impact, the shock absorbing device absorbs the impact, so that the ball screw portion is not damaged. In addition, the lubricant of the ball screw portion does not scatter and contaminate the periphery of the drive device. Moreover, since the configuration of the shielding member is simple, the manufacturing cost and maintenance cost of the drive device can be reduced.

In the present embodiment, the case where the driving device is applied to the injection molding machine has been described, but the driving device is applied to a molding machine such as a die cast machine, an IJ sealing press and other devices. can do.

Further, the present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention, and they are not excluded from the scope of the present invention.

[0061]

As described in detail above, according to the present invention, a drive device includes a hollow rotary shaft, one side end of which is attached to a mounting member, and an inner circumference of the hollow rotary shaft. A screw shaft that engages with a surface and is movably arranged in the hollow rotation shaft, projects toward the mounting member side, a nut that is screwed to the screw shaft, and the nut cannot rotate. A nut supporting member for buffering an axial shock received by the nut, a shielding member for shielding the periphery of the nut, and a driven member disposed at a side end of the screw shaft on the mounting member side. Have and.

In this case, not only is the overall length of the driving device short, the overall driving device can be miniaturized, but various driven members can be moved forward or backward simply by replacing the mounting member. High versatility. Further, even when a shock is received, the screw shaft and the nut are prevented from being damaged by buffering the shock and the scattering of the lubricant can be prevented by disposing the shielding member around the nut. it can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a drive device attached to a movable platen according to an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional drive device.

FIG. 3 is a cross-sectional view of another conventional driving device.

FIG. 4 is a schematic view of a mold clamping device of the injection molding machine according to the embodiment of the present invention.

[Explanation of symbols]

10, 10 'drive device 11, 11 'motor 17 Crosshead 24 ejector rod 33 hollow rotating shaft 37 Female Spline Hollow Shaft 41 Ball screw shaft 42 Ball screw nut 43 plates 53 Spring holder 53b Cylindrical part

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[Procedure amendment]

[Submission date] August 28, 2002 (2002.8.2)
8)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

[0022]

To this end, in a drive device of the present invention, a drive source having a hollow rotary shaft, one end of which is attached to a mounting member, and an inner peripheral surface of the hollow rotary shaft are engaged. Then, the screw shaft is disposed in the hollow rotary shaft so as to be movable back and forth, protrudes toward the mounting member side, a nut screwed to the screw shaft, and a nut that non-rotatably supports the nut.
A support member, a shielding member that shields the periphery of the nut, and a driven member disposed at a side end of the screw shaft on the mounting member side.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0061

[Correction method] Change

[Correction content]

[0061]

As described in detail above, according to the present invention, a drive device includes a hollow rotary shaft, one side end of which is attached to a mounting member, and an inner circumference of the hollow rotary shaft. A screw shaft that engages with a surface and is movably arranged in the hollow rotation shaft and that projects toward the mounting member side, a nut that is screwed to the screw shaft, and a non-rotatably support the nut.
A nut supporting member, a shielding member that shields the periphery of the nut, and a driven member disposed at a side end of the screw shaft on the mounting member side.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0062

[Correction method] Change

[Correction content]

In this case, not only is the overall length of the driving device short, the overall driving device can be miniaturized, but various driven members can be moved forward or backward simply by replacing the mounting member. High versatility. Further, by disposing the shielding member around the nut, it is possible to prevent the lubricant from scattering.

Claims (5)

[Claims] 1. A drive source having: (a) a hollow rotating shaft, one end of which is attached to a mounting member; and (b) an inner peripheral surface of the hollow rotating shaft, which engages and retracts in the hollow rotating shaft. A screw shaft that is freely arranged and projects toward the mounting member,
(C) a nut screwed onto the screw shaft; (d) a nut support member that supports the nut so that it cannot rotate and that can absorb the shock in the axial direction received by the nut; and (e) the nut. A drive device comprising: a shielding member for shielding the surroundings; and (f) a driven member arranged at a side end of the screw shaft on the mounting member side. 2. The driving device according to claim 1, wherein the driven member drives an ejector pin protruding into the mold. 3. The drive device according to claim 1, wherein the nut support member is attached via a shock absorber so as to be movable in the axial direction of the attachment member. 4. The drive unit according to claim 3, wherein the shock absorber comprises a preloaded spring element. 5. The shielding member is a cylindrical member attached to the nut supporting member, and movably engages with a hole formed in the attaching member.
The drive device according to the item.