JP2000087909A - Cylinder device performing gyratory motion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the lifetime of a cylinder device by reducing load or impact imposed on a cam groove and thereby decreasing fatigue of the cam groove. SOLUTION: In a cylinder device 1, by linearly driving a piston rod 13 in the axial direction, penetrating through a flange 14 which is also a housing and a bush 15, a can groove 30 which is provided on the outer peripheral surface of the piston rod 13 and a pin 41 which is provided on the housing are engaged, and thereby the piston rod 13 performs a gyratory motion. The cam groove 30 is formed so as to change along a quadratic curve from the beginning to the end of the gyratory motion of the piston rod 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder device in which a rod performs a linear operation and also performs a turning operation by being combined with a linear actuator that generates thrust using a fluid pressure or the like as a power source.

[0002]

2. Description of the Related Art Conventionally, in an automatic assembling apparatus or the like, a cylinder device which performs a turning operation for transporting or positioning a work is used.

[0003] In such a conventional cylinder device, the piston rod is provided so as to be able to perform both an axial linear operation and a rotational operation. A cam groove is provided on the outer peripheral surface of the piston rod, and a pin that is slidable by engaging with the cam groove is attached to the rod cover. When the piston rod performs a linear motion in the axial direction, at the same time, the piston rod rotates along the shape of the cam groove.

FIG. 4 is a development view showing a conventional cam groove 80j. In FIG. 4, the cam groove 80j is formed by
1. It comprises a rotary operating part 83 and a linear operating part 85. The linear operating portions 81 and 85 are provided on the outer peripheral surface of the piston rod at positions different from each other by 90 degrees in the circumferential direction in the cross section. Therefore, the piston rod rotates 90 degrees from the time when the pin moves from the linear operating portion 81 to the linear operating portion 85 via the rotary operating portion 83.

[0005] The rotary operating portion 83 is linear as shown in the developed view of FIG. Therefore, the angular velocity at which the piston rod rotates is a constant velocity (constant angular velocity) at the center as shown in FIG. 4B. However, at the start and end of the rotation of the piston rod, FIG.
As shown in (C), a large acceleration occurs.

[0006] In order to prevent the occurrence of excessive acceleration and reduce the impact, the boundary between the linear operation parts 81 and 85 and the rotation operation part 83 is rounded.
Is provided.

[0007]

As described above, in the conventional cylinder device, a large acceleration is generated at the start and end of the rotation of the piston rod.

That is, the piston rod rapidly turns from the linear movement in the stroke direction, and stops turning suddenly, so that an excessive load or impact is applied to the radius-shaped portions 82 and 84 which are the conversion points. . R-shaped parts 82, 8
4 provides considerable relief, but the load or stress applied by the inertia of the load is still very large.

Therefore, in the related art, the cam groove 80j is often fatigued or broken by an excessive load or impact, and there is a problem in the durability and life of this type of cylinder device. Therefore, it is necessary to limit the components mounted as the load of the piston rod, for example, the clamp arms, to small and lightweight ones. In addition, the rotation speed cannot be made too high.

The present invention has been made in view of the above problems, and has as its object to reduce the load or impact applied to a cam groove, reduce the fatigue of the cam groove, and extend the life of the cylinder device.

[0011]

According to a first aspect of the present invention, there is provided an apparatus wherein a cam groove provided on an outer peripheral surface of the rod and the housing are linearly driven in the axial direction by penetrating the housing. A cylinder device configured so that a pin provided is engaged with the rod to perform a turning operation, wherein the cam groove is configured to perform a secondary operation during a period from the start to the end of the turning operation of the rod. It is formed so as to change along a curve.

In the apparatus according to the second aspect of the present invention, the turning operation of the rod is 90 degrees, and when the rod is driven at a constant speed along the axial direction, the rod moves positively during the first 45 degrees. The cam groove is formed so as to perform an acceleration motion and perform a negative constant acceleration motion during the latter 45 degrees.

[0013]

FIG. 1 is a cross-sectional view of a cylinder device 1 according to the present invention, FIG. 2 is a cross-sectional view of the cylinder device 1 taken along line II-II, and FIG. FIG.
In FIG. 2, the portion of the flange 14 is sectioned in a direction of 45 degrees obliquely in FIG.

1 and 2, a cylinder device 1
Is composed of a cylinder tube 11, a piston 12, a piston rod 13, a flange 14, a bush 15, a head cover 16, and the like.

The piston 12 is slidable on the inner peripheral surface of the cylinder tube 11 in the axial and circumferential directions. A piston rod 13 is connected to the piston 12, and these move integrally. The piston rod 13 projects outward through the flange 14 and the bush 15. The bush 15 and the head cover 16 seal the inside of the cylinder tube 11 from the outside by packing provided on them. The bush 15, the head cover 16, the flange 14, and the cylinder tube 11 are fastened to each other by four tie bolts 17.

The head cover 16 is provided with ports 21 and 22 for supplying a pressurized fluid to the cylinder chamber. One port 21 communicates with the front cylinder chamber through a communication hole 23 provided in the cylinder tube 11.
The other port 22 communicates with the rear cylinder chamber.

The piston rod 13 is provided with a cam groove 30 on its outer peripheral surface. On the flange 14,
A pin 41 slidable by engaging with the cam groove 30 is attached. After the pin 41 is fitted in the hole of the flange 14, the pin 41 is prevented from falling out by a pressing member 52 fixed by a bolt 51.

The cam groove 30 of the piston rod 13 and the pin 41 are subjected to a surface treatment so as to have high hardness, or a metal material having high hardness is used. FIG.
, The cam groove 30 includes a linear operation part 31, a rotation operation part 32, and a linear operation part 33. The linear operating portions 31 and 33 are provided on the outer peripheral surface of the piston rod 13 at positions different from each other by 90 degrees in the circumferential direction in the cross section.

Therefore, the pin 41 is connected to the linear operating portion 31.
The piston rod 13 rotates 90 degrees during the period from the rotation operation portion 32 to the linear operation portion 33.
The rotation operating portion 32 is S-shaped as shown in the developed view of FIG. To be precise, the rotation operating part 32 is located at the point P1
From the point P3 to the point P2.
, And each is formed so as to change along a quadratic curve.

That is, the point P1 in FIG.
When the rotation angle θ is plotted on the vertical axis and the stroke L is plotted on the horizontal axis, the equation of the curve of the first half 33a is represented by θ = (βL ² ) / 2 (1). β is a coefficient.

The second half 33b is provided with a first half 33a.
Is symmetrical about the point P3. That is,
The latter half portion 33b can be expressed in the same manner as the above equation (1) by, for example, setting the point P2 as the origin and setting the rotation angle θ below the vertical axis.

The first half portion 33a and the second half portion 33b
Are connected smoothly at the point P3. In addition,
The depth of the cam groove 30 is such that the tip of the pin 41 does not hit the bottom thereof, and the width of the cam groove 30 is such that the pin 41 can move smoothly and there is no noticeable rattling.
The edge of the cam groove 30 is chamfered. Grease or the like is injected as needed.

Accordingly, when the piston rod 13 moves in the axial direction and the pin 41 passes through the rotation operating portion 32, the piston rod 13 rotates along the shape of the cam groove 30. At that time, when the piston rod 13 moves at a constant speed in the axial direction, the rotation direction becomes a positive constant acceleration in the first half portion 33a and the second half portion 33b
Then, a negative constant acceleration, that is, a constant deceleration is obtained.

In any case, as shown in FIGS. 3B and 3C, the acceleration is constant, the acceleration is evenly distributed over the entire rotary operation portion 32, and no large acceleration or impact occurs. Therefore, the load and impact applied to the cam groove 30 and the pin 41 are reduced. Thereby, the cam groove 3
The fatigue of the pins 0 and the pins 41 is reduced, and there is no possibility that they are destroyed. Therefore, the durability and life of the cylinder device 1 can be extended.

Further, the load attached to the tip of the piston rod 13 can be increased, and the load can be driven at a high speed. In the above-described embodiment, the rotation rod 32 rotates the piston rod 13 by 90 degrees.
For example, it goes without saying that the present invention can be applied to 120 degrees, 180 degrees, 45 degrees, 80 degrees, and the like. The relationship or coefficient between the rotation angle θ and the stroke L can be variously changed. The present invention can also be applied to a cylinder device operated by a power source other than the pressurized fluid, for example, an electric motor. Other, cam groove 3
The structure, shape, size, number, material, etc. of the whole or each part of the 0, the pin 41, the piston rod 13, or the cylinder device 1 can be appropriately changed in accordance with the gist of the present invention.

[0026]

According to the present invention, the load or impact applied to the cam groove can be reduced, the fatigue of the cam groove can be reduced, and the life of the cylinder device can be extended.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cylinder device according to the present invention.

FIG. 2 is a sectional view of the cylinder device taken along line II-II.

FIG. 3 is a development view showing a cam groove.

FIG. 4 is a development view showing a conventional cam groove.

[Explanation of symbols]

 Reference Signs List 1 cylinder device 13 piston rod (rod) 14 flange (housing) 15 bush (housing) 30 cam groove 41 pin

Claims (2)

[Claims] A rod is pivotally operated by penetrating a housing and linearly driving the rod in the axial direction so that a cam groove provided on an outer peripheral surface of the rod engages with a pin provided on the housing. Wherein the cam groove is formed so as to change along a quadratic curve from the start to the end of the turning operation of the rod. A cylinder device for performing a turning operation characterized by the following. 2. The rotating motion of the rod is 90 degrees, and when the rod is driven at a constant speed along the axial direction, a positive constant acceleration motion is performed during the first 45 degrees and the second 45 degrees. The cylinder device that performs the turning operation according to claim 1, wherein the cam groove is formed so as to perform a negative constant acceleration movement between the cam grooves.