JPH11201255A - Overload protective device in constraint translation cam device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an overload protective device in a constraint translation cam device which can make in a small size, and can set a large permissible load. SOLUTION: This is a device to protect the overload in a translation cam device which reciprocates an operation member 1 guided by a translation guide 2 by a constraint cam 3. While the base ends of links 10a and 10b are connected rotatively to the arm ends of a U-shape arm member 8, a toggle mechanism 5 with the structure supporting a roller follower 6 through pins inserted to the tips of the both links 10a and 10b which are crossed at an angle to each other is set to the operation member 1, and the roller follower 6 and the cam 3 of the toggle mechanism 5 are engaged, and furthermore, the cam 3 is constrained between the follower 6 and a receiver roller 7 provided in the operation member 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overload protection device for a restrained linear motion cam device.

[0002]

2. Description of the Related Art Conventionally, a device for protecting an overload in a constrained linear motion cam device has generally been constructed using a sub-linear motion guide as shown in FIG. 8 or FIG. In FIG. 8, 5
Reference numeral 1 denotes a sub-linear guide, which is provided between a first operating member 53 and a second operating member 54 guided by a main linear guide 52, and the second operating member 54 is guided by a sub-linear guide 51. It is to be done. Reference numeral 55 denotes a cam, which is restricted by two cam followers 56 provided on the first operating member 53. Reference numeral 57 denotes a compression spring, which opposes a load applied to the second operating member 54. Cam Follower 5
By rotating the cam 55 constrained by 6 around the shaft 58, the first operating member 53 on which the second operating member 54 is mounted moves along the main linear guide 52. In FIG. 9, reference numeral 61 denotes a sub-linear guide, and a first operating member 63 guided by a main linear guide 62.
And the second operating member 64, so that the second operating member 64 is guided by the sub-linear guide 61. A cam 65 is restrained by two cam followers 66 provided on the first operating member 63 and the second operating member 64, respectively. 67 is a compression spring, and 68 is a bridge. The cam 65, which is constrained by the cam follower 66, is rotated around a shaft 69 to transmit stress to the first operating member 63.

[0003]

The conventional overload protection device as described above has a structure using a sub-linear motion guide, so that the whole constrained linear motion cam device becomes large and the weight increases, so that high speed operation is required. There is a problem that it is difficult to cope with the operation. Further, the device shown in FIG. 8 has a problem in that the protection capability is reduced when the spring force of the compression spring 57 is strengthened because the structure directly receives the load and is not opened in the event of an overload. Further, in the device shown in FIG. 9, the cam follower 6 is actuated by the reaction force moment acting as indicated by arrow 70.
6 has a problem that the cam 65 hits one side. In addition, there is a structure that can withstand a large load by using a shear pin. However, since there is no resilience and poor reproducibility, the reliability of the set allowable load is lacking.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an overload protection device in a constrained linear motion cam device which can be reduced in size and can set a large allowable load. The purpose is.

[0005]

According to the overload protection device of the present invention having the above object, a toggle mechanism is provided between an operating member and a cam, and a roller follower constituting the toggle mechanism is mounted on the cam. It is designed to be engaged and restrained.

That is, the first aspect of the present invention is an apparatus for protecting an overload in a linear motion cam device for reciprocating an operating member guided by a linear motion guide with a restraining cam, wherein the operating member has a U-shape. A toggle mechanism with a structure in which the base end of the link is rotatably connected to each arm end of the arm member and the roller follower is supported via a pin inserted at the tip of both links crossed at an angle The roller follower of the toggle mechanism is engaged with a cam, and the cam is restrained between the roller follower and a receiving roller provided on an operating member. .

According to a second aspect of the present invention, there is provided a device for protecting an overload in a linear motion cam device for reciprocating an operating member guided by a linear guide with a restraining cam, wherein a load applied to the operating member is reduced. A toggle having a structure in which a base end of a link is rotatably connected to each arm end of a U-shaped arm member, and a roller follower is supported via a pin inserted at a tip end of both links crossing at an angle. An overload protection device characterized by being configured to be transmitted to a cam side via a mechanism.

[0008]

According to the overload protection device in the restricted linear motion cam device of the present invention, it is possible to reduce the size and weight of the device without the intervention of the auxiliary linear motion guide as in the conventional device. Further, by interposing the toggle mechanism, a large load can be countered with a small displacement.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of a constrained linear cam apparatus corresponding to the conventional constrained linear cam apparatus shown in FIG. Reference numeral 1 denotes an operating member, which is guided by a linear motion guide 2. A cam 3 is installed adjacent to the operating member 1 so as to be rotatable about a shaft 4, and the cam 3 and the operating member 1
A roller follower 6 of a toggle mechanism 5 installed on one side of
It is restrained by a receiving roller 7 installed on the other side of the operating member 1.

The toggle mechanism 5 has a structure as shown in FIGS. 2 to 5, and has two opposite arms 8 of a U-shaped arm member 8 fixed to the operating member 1.
links 10a, 10b at the tips of
Are connected rotatably at the base end of
0a, 10b are crossed at an angle so that the tips of the U-shaped arm members 8 protrude outward.
The roller follower 6 is rotatably supported via a pin 11 inserted in the intersection. Link 1
Reference numerals 0 a and 10 b are provided symmetrically on both side surfaces of the U-shaped arm member 8.

FIG. 6 shows a second embodiment of a constrained linear cam apparatus corresponding to the conventional constrained linear cam apparatus shown in FIG. An operating member 12 is guided by a linear guide 13. A cam 14 is installed adjacent to the operating member 12 so as to be rotatable around a shaft 15, and the cam 14 and the operating member 12 are provided on one side of the operating member 12. It is restrained by a roller follower 6 and a receiving roller 16 installed on the other side of the operation member 12.

In the embodiment as described above, the cams 3, 1
When the operating members 1 and 12 are operated at 4, a load is applied to the operating members 1 and 12 as indicated by an arrow 17, and this load is transmitted to the cams 3 and 14 via the roller follower 6 of the toggle mechanism 5. Will be. When a load stress acts on the toggle mechanism 5, the arms 8a and 8b and the links 10a and 10b bend and the roller follower 6 is displaced inward of the U-shaped arm member 8. Here, the roller follower 6 of the toggle mechanism 5
FIG. 7 shows the relationship between the load acting on the motor and the displacement. Since the region A in the figure is a region where displacement caused by initial gap absorption and the like is large, the state is shifted to the region B by applying a preload corresponding to a load exceeding the region A in advance so that the load is reduced. Therefore, the variation of the displacement of the roller follower 6 can be minimized with respect to the variation, and the accurate and stable positioning of the operating members 1 and 12 can be achieved while maintaining the restrained state of the cams 3 and 14. As is clear from the graph in the region B, a relatively large allowable load range can be secured. When a load large enough to shift to the region C is applied, the roller follower 6 is largely displaced and the cams 3, 1 are displaced.
4 is released, so that overload is protected. When the restraint of the cams 3 and 14 is released by the overload, after removing the cause of the overload, the U-shaped arm member 8 of the toggle mechanism 5 is removed.
By returning the roller follower 6 displaced inward to the outside by using a suitable tool or the like, it is possible to return to the restrained state again.

As shown by the chain line in FIG. 7, the relationship between the displacement of the roller follower 6 and the load is determined by selecting the length and width of the links 10a and 10b and the length and width of the arms 8a and 8b. It is possible to change the load that falls within the region B, that is, the range of the allowable load. Therefore, the allowable load can be set according to the purpose of use of the restricted linear motion cam device, and a large allowable load range can be set.

By configuring the overload protection device of the restrained linear motion cam device as in the embodiment, a sub-linear motion guide is not required, and the size of the overload protection device can be reduced. Since an expensive member having high rigidity such as a sub-linear motion guide is provided, not only can it be inexpensive, but also the weight of the entire constrained cam device can be reduced, and the device can respond to high speed. Become like Moreover, by incorporating the toggle mechanism 5, a large allowable load can be set, and the arms 8a and 8b of the toggle mechanism 5 and the links 10a and 10b can be set.
The range of the allowable load can be set within a necessary range by selecting the above.

As described above, the toggle mechanism 5 has a structure in which the links 10a and 10b are provided symmetrically on both sides of the U-shaped arm member 8, so that no moment is generated when a load is applied, and Collision with the follower 6 is avoided.

[0017]

As described above, according to the present invention, since the cam of the restrained linear motion cam device is restrained by the roller follower of the toggle mechanism, the size can be reduced and a large allowable load can be set. An overload protection device in a restricted linear motion cam device that can be provided can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a first embodiment of the present invention.

FIG. 2 is a perspective view of a toggle mechanism used in the embodiment.

FIG. 3 is a front view of the toggle mechanism.

FIG. 4 is a plan view of the toggle mechanism.

FIG. 5 is a side view of the toggle mechanism.

FIG. 6 is a configuration diagram illustrating a second embodiment of the present invention.

FIG. 7 is a graph showing a relationship between a load and a displacement of a roller follower constituting a toggle mechanism.

FIG. 8 is a configuration diagram illustrating an outline of a conventional overload protection device.

FIG. 9 is a configuration diagram illustrating an outline of another conventional overload protection device.

[Explanation of symbols]

 1, 12 Operating member 2, 13 Linear guide 3, 14 Cam 4, 15 shaft 5 Toggle mechanism 6 Roller follower 7, 16 Receiving roller 8 U-shaped arm member 8a, 8b Arm 9, 11 pin 10a, 10b Link

Claims (2)

[Claims] An apparatus for protecting an overload in a linear motion cam device that reciprocates operating members (1) and (12) guided by linear motion guides (2) and (13) with constraining cams (3) and (14). 12, the base ends of the links 10a and 10b are rotatably connected to the ends of the arms 8a and 8b of the U-shaped arm member 8, and are inserted through the distal ends of the two links 10a and 10b crossed at an angle. A toggle mechanism 5 having a structure that supports the roller follower 6 via the pin 11 is installed,
The roller follower 6 of the toggle mechanism 5 is engaged with the cams 3 and 14, and the cams 3 and 14 are restrained between the roller follower 6 and the receiving rollers 7 and 16 provided on the operating members 1 and 12. An overload protection device characterized in that: 2. A device for protecting an overload in a linear motion cam device which reciprocates operating members 1 and 12 guided by linear motion guides 2 and 13 by constraining cams 3 and 14; Is applied to the U-shaped arm member 8.
The bases of the links 10a and 10b are rotatably connected to the ends of the arms 8a and 8b, and the roller follower 6 is connected to the ends of the links 10a and 10b at an angle by way of pins 11 inserted into the tips of the links 10a and 10b. An overload protection device configured to be transmitted to the cams 3 and 14 via a toggle mechanism 5 having a supported structure.