JPH0893805A - Clamp device of rotating shaft - Google Patents

Abstract

PURPOSE: To provide a clasp device of a rotating shaft by which the rotating shaft can be clamped without any play and also the rotating shaft can be clamped in a desired stopping position with high accuracy. CONSTITUTION: This clamp device is provided with a spur gear 4 fixed at one end of a rotating shaft 3, a fixing member 9 opposite to the spur gear 4, a disk 10 pressed down to the fixing member 9 and a thin plate 11 interposed between the spur gear 4 and the disk 10 for rotatably connecting the spur gear 4 integratedly with the disk 10 and making the disk 10 displaceable to the spur gear 4 in the axial direction of the rotating shaft 3. When the disk 10 is pushed to the fixing member 9 side, the disk 10 is displaced in the axial direction to the spur gear 4 and pressed down to the fixing member 9 with the deformation of the thin plate 11, so that the disk 10 may be clamped to the fixing member 9 by the friction of the fixing member 9. Since the disk 10 and the spur gear 4 are connected in the rotating direction of the rotating shaft 3 by the thin plate 11 without any rattle, the rotating shaft can be clamped without any play.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary shaft clamp device, and more particularly to a rotary shaft clamp device applicable to a rotary device such as a probe rotary device of a coordinate measuring machine.

[0002]

2. Description of the Related Art Conventionally, as a clamp device for such a rotary shaft, for example, a friction plate is splined to a hub fixed to the rotary shaft of the rotary device, and the friction plate is pressed against a fixing member. It is known that the rotating shaft is clamped to stop its rotation, or the pressing of the friction plate against the fixing member is released so that the rotating shaft can freely rotate (for example, Japanese Patent Publication No. 61-34007). Gazette).

[0003]

However, in the above-mentioned prior art, the friction plate is spline-coupled to the hub fixed to the rotating shaft, and there is play between the friction plate and the rotating shaft in the rotating direction of the rotating shaft. Therefore, there is a problem in that the rotary shaft cannot be clamped without rattling, and the rotary shaft cannot be clamped at a desired position with high accuracy.

The present invention has been made in view of such conventional problems, and the problem is that the rotating shaft can be clamped without rattling, and the rotating shaft can be clamped with high precision at a desired position. An object of the present invention is to provide a clamp device for a rotating shaft.

[0005]

In order to solve the above-mentioned problems, a clamp device for a rotary shaft according to a first aspect of the present invention,
A first member fixed to one end surface of the rotating shaft, a fixing member facing the first member, a second member pressed against the fixing member, and interposed between the first member and the second member. And a thin plate that integrally and rotatably connects the first member and the second member and that allows the second member to be displaced with respect to the first member in the axial direction of the rotation shaft. ing.

According to a second aspect of the present invention, a clamp device for a rotary shaft has one end portion having a short length from a rotation fulcrum and the other end portion having a long length from the rotation fulcrum. One end is lifted by the biasing force of the biasing member to push the second member against the fixing member, and the other end of the lever member is lifted against the biasing force of the biasing member, And a pressing state releasing means for releasing the pressing state of the second member with respect to the fixed member.

[0007]

In the clamp device for a rotary shaft according to claim 1, when the second member is pushed toward the fixing member, the thin plate is deformed,
The second member is axially displaced with respect to the first member and pressed against the fixed member, and the second member is clamped to the fixed member by friction with the fixed member. At this time, the second member and the first
Since the members are joined by the thin plate in the rotating direction of the rotating shaft without rattling, the rotating shaft is clamped without rattling.

According to a second aspect of the present invention, in the clamp device for a rotating shaft, the length between the rotation fulcrum and one end of the lever member is a, and the length between the rotation fulcrum and the other end of the lever member is a. If the length is b and the urging force of the urging member is F, then a <b. Therefore, the other end of the lever member is lifted against the urging force of the urging member, and the second member with respect to the fixing member is lifted. The force F ′ of the pressed state releasing means required to release the pressed state of F is F ′ = a /
It becomes bF, and F ′ can be made smaller than F.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a probe rotating device of a coordinate measuring machine equipped with a rotating shaft clamping device according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. It is a figure.

As shown in FIG. 1, on a base 1 of a probe rotating device of a coordinate measuring machine, a cylindrical rotating shaft 3 is rotatable forward and backward through bearings 2a and 2b and is not displaceable in the axial direction. It is supported. A spur gear (first member) 4 is fixed to one end surface of the rotating shaft 3 with a screw 5, and a probe (not shown) is fixed to the other end surface. The rotation of the motor (not shown) is transmitted to the spur gear 4 via a reduction gear (not shown), so that the rotating shaft 3 rotates integrally with the spur gear 4. Further, a rotary encoder 6 for reading the rotation angle of the rotary shaft 3 and a reading head 7 are built in.

The clamp device for the rotary shaft mounted on the probe rotating device of the coordinate measuring machine is a spur gear 4 and a fixing device that is opposed to the spur gear 4 and is fixed to one end surface of the base 1 by bolts 8a and 8b. The member 9, the disc (second member) 10 pressed against the fixing member 9, and the spur gear 4 and the disc 10 are interposed between the spur gear 4 and the disc 10 so as to be integrally rotatable, and An annular thin plate 11 that allows the disc 10 to be displaced with respect to the spur gear 4 in the axial direction of the rotating shaft 3.

The thin plate 11 is a leaf spring made of a spring material that can be bent by a slight force. The thin plate 11 is fixed to the upper surface of the spur gear 4 by three screws 12 arranged at substantially equal intervals in the circumferential direction, and at the lower surface of the disk 10 at substantially equal intervals in the circumferential direction. It is fixed by three screws 13 arranged one at an intermediate position between the adjacent screws 12. That is, the same number of screws 12 and screws 13 are alternately arranged at substantially equal intervals. As a result, the spur gear 4 and the disc 10 rotate integrally due to the rigidity of the thin plate 11, and the disc 10 is displaced in the axial direction of the rotary shaft 3 with respect to the spur gear 4 by the elastic deformation of the thin plate 11. 4 and the disk 10 are connected via a thin plate 11.

The rotary shaft clamping device is shown in FIGS.
As shown in FIG. 2, one end 21a is provided on the upper surface side of the base 1 so as to be swingable around the pin 20 as a fulcrum, and the length from the center (rotation fulcrum) of the pin 20 is short and the length from the rotation fulcrum. Has a long end 21b, and the one end 21a side is lifted by the urging force of a spring (urging member) 22 to press the disk 10 against the fixing member 9, and the other end of the lever member 21. 21b side is lifted against the biasing force of the spring 22,
Solenoid 2 as pressing state releasing means for releasing the pressing state (clamping state) of the disk 10 against the fixing member 9.
3 and 3.

Lever member 21, spring 22 and solenoid 2
3 are provided at both ends of the disk 10 so that the central parts of both ends of the disk 10 are pressed against the fixing member 9 or the central parts of both ends are separated from the fixing member 9. At the center of the lower surface of both ends of the disk 10, Vs opened downward
The pressing members 24 each having the groove 24a (see FIG. 3) are fixed.

At the upper end of each lever member 21 on the one end 21a side, a V groove 21c opened upward so as to sandwich the ball 25 with the V groove 24a of each pressing member 24 (see FIG. 3).
(See) is provided. One end 21 of each lever member 21
A spring 22 is interposed between the lower part on the a side and the bottom surface of the spring accommodating portion 1a of the base 1, and the disc 22 via the one end 21a of the lever member 21, the ball 25 and the pressing member 24 by the urging force of the spring 22. The central portions of both ends of 10 are pressed against the fixing member 9.

On the other hand, in the lower part of the other end 21b of each lever member 21, a V groove 21d opened downward (see FIG. 3).
Is provided. Each V groove 21d and each solenoid 2
The sphere 26 is sandwiched between the shaft 23a and the shaft 23a, and the thrust force of each solenoid 23 generated at the time of energization causes the shaft 23a to resist the biasing force of the spring 22 on the other end 21b side of each lever member 21 via the ball 26. Then, the disc 10 is lifted up and released from the pressing state (clamping state) of the disk 10 against the fixing member 9.

Next, the operation of the rotary shaft clamping device will be described.

When each solenoid 23 is energized,
The thrust force of each solenoid 23 causes the shaft 23a to lift the other end 21b side of each lever member 21 through the ball 26 against the biasing force of the spring 22, whereby the fixing member 9 and the disc 10 are moved.
A slight gap s (see FIG. 3) is formed between the and, and the disc 10 is pressed against the fixing member 9 (clamping state).
Is released (see FIGS. 1 to 4). At this time, the rotation of the motor (not shown) is transmitted to the spur gear 4 via a reduction gear (not shown), and the rotary shaft 3 rotates integrally with the spur gear 4.

When the rotary encoder 6 and the reading head 7 read the rotation angle of the rotary shaft 3, if the energization of each solenoid 23 is stopped, each solenoid 2 is stopped.
The shaft 23a of No. 3 retracts as shown in FIG.
One end 21a of each lever member 21 and the ball 2 by the urging force of
5, the pressing member 24 and the central portion of both ends of the disk 10 are lifted (see FIG. 5). At this time, the thin plate 11 is shown in FIG.
6 is elastically deformed from the state shown in FIG. 6 to the state shown in FIG.
The central portions of both ends of 0 are pressed against the fixing member 9, and the disk 10 is clamped to the fixing member 9 by friction with the fixing member 9. At this time, since the disc 10 and the spur gear 4 are coupled to each other by the thin plate 11 in the rotating direction of the rotating shaft 3, the rotating shaft 3 is clamped without rattling (see FIGS. 5 and 6). Therefore, the rotary shaft 3 can be clamped without rattling, and the rotary shaft 3 can be clamped with high accuracy at a position where it is desired to stop.

After the rotary angle of the rotary shaft 3 is read by the rotary encoder 6 and the read head 7, when the solenoids 23 are energized again, the thrust of each solenoid 23 causes the shaft 23a to move through the sphere 26 to each lever member. The other end 21b side of 21 is lifted against the biasing force of the spring 22,
As a result, a slight gap s (see FIG. 3) is formed between the fixing member 9 and the disk 10, and the disk 10 with respect to the fixing member 9 is formed.
The pressed state (clamping state) is released, and the rotary shaft 3 rotates integrally with the spur gear 4.

According to the above embodiment, as shown in FIG. 3, the length between the rotation fulcrum (center of the pin 20) and the center of the sphere 25 on the side of the one end 21a of the lever member 21. Is a, the length between the rotation fulcrum and the center of the sphere 26 on the other end 21b side of the lever member 21 is b, and the urging force of the spring 22 is F, then a <b. , The thrust F'of the solenoid 23 required to lift the other end 21b of the lever member 21 against the biasing force of the spring 22 to release the clamped state of the disk 10 against the fixed member 9 is F '= a / BF
Therefore, F ′ can be made smaller than F. Therefore, even when the biasing force F of the spring 22 is increased and the disc 10 is pressed against the fixing member 9 with a large clamping force, the clamp can be easily released with a thrust F ′ smaller than the biasing force F. Alternatively, when a large clamping force is not required, the solenoid 23 may be small in size, which enables downsizing of the device.

Further, according to the above embodiment, as described above, when the energization of each solenoid 23 is stopped, each spring 2 is stopped.
The disc 10 is lifted by the urging force of 2, which causes the thin plate 11 to elastically deform.
Is displaced in the axial direction with respect to the spur gear 4, but since the thin plate 11 is slightly deformed, no unreasonable force is applied to the rotary shaft 3 and the rotary shaft 3 is not deformed.

According to the above embodiment, the thin plate 11 is
It is fixed to the upper surface of the spur gear 4 by three screws 12 arranged at substantially equal intervals in the circumferential direction, and is fixed to the lower surface of the disk 10 at substantially equal intervals in the circumferential direction and of adjacent screws 12. Three screws 13 arranged one at an intermediate position
Is fixed by. That is, since the same number of screws 12 and screws 13 are alternately arranged at substantially equal intervals, the thin plate 11 elastically deforms between the screws 12 and 13 substantially uniformly, and the disk 10 becomes uniform. It is pressed against the fixing member 9 with a sufficient force.

In the above embodiment, the thin plate 11 and the spur gear 4 and the thin plate 11 and the disk 10 are fixed by screws, but they may be fixed by welding without using screws.

In the above embodiment, the solenoid 23 is used as the pressed state releasing means, but a mechanical releasing means using a spring or the like may be used instead of the solenoid.

[0027]

As described above, according to the clamp device for a rotary shaft according to the invention described in claim 1, when the second member is pushed toward the fixed member side, the thin plate is deformed so that the second member becomes the first member. The member is axially displaced with respect to the member and pressed against the fixed member, and the second member is clamped by the fixed member by friction with the fixed member. At this time, the second member and the first member are thin plates of the rotary shaft. Since they are connected in the rotating direction without rattling, the rotating shaft can be clamped without rattling, and the rotating shaft can be clamped with high precision at the position where it is desired to stop.

According to the second aspect of the present invention, the length between the rotation fulcrum and one end of the lever member is a, and the rotation fulcrum and the other end of the lever member are a. Let b be the length between them and F be the urging force of the urging member.
Therefore, the force F ′ of the pressing state releasing means required to release the pressing state of the second member against the fixed member by lifting the other end of the lever member against the urging force of the urging member, F
Since ′ = a / bF, F ′ can be made smaller than F. Therefore, even when the urging force F is increased and the second member is pressed against the fixing member with a large clamping force, the clamp can be easily released with a force F ′ smaller than the urging force F. Alternatively, when a large clamping force is not required, the pressed state releasing means may be small in size, and the device can be downsized.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a probe rotating device of a coordinate measuring machine equipped with a rotating shaft clamping device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged view of a part of FIG. 2, and is an operation explanatory diagram showing a clamp release state.

FIG. 4 is an enlarged view of a part of FIG. 1, and is an operation explanatory view showing a clamp release state.

5 is a view similar to FIG. 3 and is an operation explanatory view showing a clamped state.

FIG. 6 is a diagram similar to FIG. 4, and is an operation explanatory diagram showing a clamped state.

[Explanation of symbols]

 3 Rotating Shaft 4 Spur Gear 9 Fixing Member 10 Disc 11 Thin Plate 21 Lever Member 21a One End 21b The Other End 22 Spring 23 Solenoid

Claims (2)

[Claims] 1. A first member fixed to one end surface of a rotating shaft, a fixing member facing the first member, a second member pressed against the fixing member, the first member and the second member. And the first
And a thin plate that integrally and rotatably connects the member and the second member, and that is capable of displacing the second member in the axial direction of the rotation shaft with respect to the first member. Clamping device for rotating shaft. 2. An end portion having a short length from a rotation fulcrum and another end portion having a long length from the rotation fulcrum, the one end portion being lifted by an urging force of an urging member. A lever member that presses the second member against the fixing member, and a pressing member that lifts the other end of the lever member against the urging force of the urging member to release the pressing state of the second member against the fixing member. The rotary shaft clamping device according to claim 1, further comprising a state releasing means.