JPH11280710A - Cylinder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a cost by providing a retainer for forming a pressure chamber in a cylinder tube, a cylinder head adjacent to this, a pressure chamber side cushion hole of the retainer inner peripheral surface and a cushion ring in the hole. SOLUTION: While the opening part 1a is formed by diametrically expanding the inner peripheral surface end part of a cylinder tube 1, the inner peripheral surface of a cylindrical retainer 3 is composed of a cushion hole 16 formed on the pressure chamber 36 side and an inserting hole 26 having a diameter formed larger than this, and a stopper 27 positioned in a pressure chamber 36 side opening is integrally formed. The inserting cylinder part 29 having the same length as the inserting hole 26 is integrally formed in a tubular cylinder head 4, and a metallic or synthetic resin cushion ring 17 is installed in the cushion hole 16 from the inserting hole 26 side. Therefore, when the cushion ring 17 is incorporated into the cushion hole 16, a stop ring and snap ring are obviated to reduce the number of part items as well as to reduce a cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder device having a cushion function.

[0002]

2. Description of the Related Art As a conventional cylinder device, for example,
There were those shown in FIGS. As shown in FIG. 4, a rod 2 is incorporated in a cylinder tube 1. The rod 2 is provided with a piston at a position (not shown) on the left side of the drawing. After the piston and the rod 2 are incorporated into the cylinder tube 1, the cylinder tube 1
Then, the cylindrical retainer 3 and the cylindrical cylinder head 4 are assembled as follows.

[0003] The end of the retainer 3 is inserted into the open end of the cylinder head 4 so that the retainer 3 and the cylinder head 4 are coaxially adjacent to each other. The connecting member 7 having a shape of a circle is fitted. As shown in FIG. 5, the ring-shaped connecting member 7 is divided radially, and includes a retainer 3 and a cylinder head 4.
It is assembled from the outer peripheral surface side. A ring 8 for holding the assembled state is fitted in a fitting groove 23 formed on the outer peripheral surface of the connecting member 7. Therefore, the retainer 3 and the cylinder head 4 are connected by the connecting member 7 and the ring 8.

The above-mentioned connected retainer 3 and cylinder head 4 are inserted into the cylinder tube 1, and the outer peripheral surface of the cylinder head 4 is screwed and fixed to the inner peripheral surface end of the cylinder tube 1. At this time, the rod 2 is slidably supported by a bearing 9 provided on the inner peripheral surface of the cylinder head 4. Further, the ring-shaped seal member 10 is sandwiched between the retainer 3 and the cylinder head 4, and the seal member 10 is pressed against the outer peripheral surface of the rod 2 to prevent leakage from the outer peripheral surface of the rod 2. On the inner peripheral surface of the retainer 3, a clearance is secured between the retainer 3 and the rod 2 so that the flow path 11
Is formed.

[0005] When the retainer 3 and the cylinder head 4 are assembled to the cylinder tube 1 in this manner, a pressure chamber 36 is formed in the cylinder tube 1 by the retainer 3 and a piston (not shown). The communication passage 12 formed in the radial direction of the retainer 3 is connected to the cylinder tube 1.
The port 13 is formed to communicate with the port 13. Therefore,
The port 13 communicates with the flow path 11 on the inner peripheral surface of the retainer 3 via the communication passage 12.

Here, a cushion hole 16 having a diameter larger than that of the flow path 11 is formed on the inner peripheral surface of the retainer 3 on the pressure chamber 36 side. Therefore, a step 20 is formed at a portion where the cushion hole 16 and the flow path 11 are continuous. A ring-shaped cushion ring 17 made of metal or synthetic resin is incorporated in the cushion hole 16. The cushion ring 17 has an outer diameter slightly smaller than the diameter of the cushion hole 16, and
It has an inner diameter slightly larger than the diameter of the cushion bearing 22 provided on the rod 2. Therefore, when the rod 2 strokes rightward in the drawing, the cushion bearing 22
Is inserted into the inner peripheral surface of the cushion ring 17.

After the cushion ring 17 is installed, a ring-shaped stop ring 18 is installed in the cushion hole 16 from the pressure chamber 36 side. The stop ring 18 has an outer diameter substantially equal to the diameter of the cushion hole 16 and is press-fitted into the cushion hole 16. And
The inner diameter is larger than the diameter of the cushion ring 17. Furthermore, at the opening end of the cushion hole 16,
In order to prevent the stop ring 18 from coming off, a substantially C-shaped snap ring 19 is fitted.

The cushion ring 17 can move in the cushion hole 16 in the axial direction until it comes into contact with the stop ring 18 or the step 20 on the inner peripheral surface of the retainer 3. And this cushion ring 1
7, a plurality of relay grooves 21 are radially formed on the end face on the stop ring 18 side, as shown in FIG.

On the outer peripheral surfaces of the retainer 3 and the cylinder head 4, O-rings 14, 1
5 are provided. Then, the O-ring 14 on the retainer 3 side
Thus, leakage between the port 13 and the pressure chamber 36 is prevented, and leakage to the outside of the cylinder tube 1 is prevented by the O-ring 15 on the cylinder head 4 side.

Next, the operation of the conventional cylinder device will be described. Now, it is assumed that the port 13 communicates with a tank (not shown) and the rod 2 is stroked rightward in the drawing. When the rod 2 is stroked and the cushion bearing 22 is inserted into the inner peripheral surface of the cushion ring 17, a throttle effect is exerted by the clearance between the outer peripheral surface of the cushion bearing 22 and the inner peripheral surface of the cushion ring 17. Therefore, a pressure difference occurs before and after the cushion ring 17, and the cushion ring 17 moves toward the flow channel 11 and is pressed against the step portion 20.

Then, the cushion ring 17 is
In the state where the pressure chamber 36 is pressed against the inner surface of the cushion ring 17 and the cushion bearing 22, the pressure chamber 36 and the flow path 11 are in contact with each other.
Communicates only through the clearance with the outer peripheral surface. Therefore, the oil pressure in the pressure chamber 36 increases due to the effect of reducing the clearance, so that the cushion effect can be exerted. Thus, the rod 2 strokes,
When a piston (not shown) approaches the retainer 3, a cushion effect is exerted to prevent the piston from colliding with the retainer 3.

Conversely, when pressure oil is supplied to the port 13 from the above state, a differential pressure is generated across the cushion ring 17, and the cushion ring 17 moves to the pressure chamber 36 side and stops. It contacts the ring 18. Therefore, the flow path 11 is formed in a space between the inner peripheral surface of the cushion hole 16 and the outer peripheral surface of the cushion ring 17 → the cushion ring 17
Thus, the rod 2 can be quickly stroked by communicating with the pressure chamber 36 via the relay groove 21 formed at the bottom.

[0013]

In the above-described conventional cylinder device, the cushion hole 16 is formed in the inner peripheral surface of the retainer 3.
And the flow path 1 having a smaller diameter than the cushion ring 17
1 are formed. Therefore, when assembling the cushion ring 17 into the cushion hole 16, the cushion ring 17 cannot be assembled from the flow channel 11 side, but must be assembled from the pressure chamber 36 side. Therefore, after the cushion ring 17 is incorporated, a stop ring 18 as a separate member is provided in the cushion hole 16.

The stopper ring 18 must be firmly fixed so that it can withstand a high load because the cushion ring 17 is in contact with the stopper ring 18. Therefore, the snap ring 19 must be further used to restrict the stopper ring 18 from coming off. However, if the stopper ring 18 and the snap ring 19 are assembled in this manner,
As the number of parts increases, the man-hours for assembling also increase, and the cost increases. An object of the present invention is to provide a cylinder device capable of reducing costs by reducing the number of parts and the number of assembling steps.

[0015]

A first aspect of the present invention relates to a cylinder device, and forms a pressure chamber in combination with a cylinder tube, a rod incorporated in the cylinder tube, a piston provided in the rod, and a piston in the cylinder tube. A cylindrical retainer, a cylinder head attached to the end of the cylinder tube adjacent to the retainer, a cushion hole formed on the pressure chamber side of the inner peripheral surface of the retainer, and an axially movable inside the cushion hole. A cushion ring, an insertion hole formed on the cylinder head side from the cushion hole on the inner peripheral surface of the retainer, and formed at least with the retainer and an insertion hole having a diameter larger than that of the cushion ring, and positioned at the pressure chamber side opening of the cushion hole. And a cylinder member inserted into the insertion hole and linked to the cylinder head. A relay groove formed in the radial direction of the end surface on the stopper side of the shock ring, a port formed in the cylinder tube, and a communication passage communicating the port with the flow path on the inner peripheral surface of the cylindrical member, the rod is stroked, When the specified position of the rod is inserted into the inner peripheral surface of the cushion ring,
A throttle effect is exerted between the predetermined position of the rod and the inner peripheral surface of the cushion ring, and the cushion ring is configured to move in the axial direction within a range until it comes into contact with the stopper or the end of the cylindrical member. It is characterized by points.

A second invention is characterized in that, in the first invention, a cylindrical member is formed integrally with a cylinder head. In a third aspect based on the first aspect, the cylinder member is formed separately from the cylinder head, and a communication groove is formed on an adjacent surface of one of the retainer and the cylinder head.
When the retainer and the cylinder head are adjacent to each other, the communication groove and the adjacent surface of the other of the retainer and the cylinder head are combined to form a communication passage that communicates the port with the flow path.

According to a fourth aspect, in the first to third aspects,
An opening formed by expanding the end of the inner peripheral surface of the cylinder tube, a step formed in the cylinder tube by the inner bottom surface of the opening, and a flange provided on the outer peripheral surface of the retainer; It is characterized in that when the head is inserted into the opening and fixed at a predetermined position, the flange of the retainer is pressed against the step in the cylinder tube. In a fifth aspect based on the first to fourth aspects, the taper formed on any one end surface of the cushion ring and the taper of the cushion ring are provided on either the stopper side or the end side of the cylindrical member. It is characterized by having a formed inclined surface.

[0018]

1 and 2 show a first embodiment of a cylinder device according to the present invention. However, the following description focuses on differences from the above-described conventional example, and the same components are denoted by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 1, an opening 1 a is formed by enlarging the end of the inner peripheral surface of the cylinder tube 1. Therefore, a step 24 is formed in the cylinder tube 1 by the inner bottom surface of the opening 1a. The port 13 formed in the cylinder tube 1 is located at the opening 1a.

On the other hand, the inner peripheral surface of the cylindrical retainer 3 includes a cushion hole 16 formed on the pressure chamber 36 side and an insertion hole 26 formed with a diameter larger than the cushion hole 16. On the inner peripheral surface of the retainer 3, a stopper 2 positioned at an opening of the cushion hole 16 on the pressure chamber 36 side is provided.
7 are integrally formed. Further, a flange 28 is formed on the outer peripheral surface of the retainer 3 at the end on the cylinder head 4 side.

The cylindrical cylinder head 4 is formed integrally with an insertion cylinder 29 having the same length as the insertion hole 26. The insertion tube portion 29 is inserted into the insertion hole 26 of the retainer 3, and the retainer 3 and the cylinder head 4 are coaxially arranged. Here, the insertion cylinder portion 29 of the cylinder head 4 is inserted into the insertion hole 26 of the retainer 3.
When inserted into the cushion hole 16, the insertion hole 26
A ring-shaped cushion ring 17 made of metal or synthetic resin is assembled from the side.

The cushion ring 17 is such that the cushion bearing 22 provided at a predetermined position of the rod 2 is inserted into the inner peripheral surface of the cushion ring 17 as described in the conventional example. As shown in FIG. 2, a plurality of relay grooves 21 are formed radially on the end face on the stopper 27 side. The number of the relay grooves 21 is not limited at all. The cushion ring 17 thus configured can move in the cushion hole 16 in the axial direction until it comes into contact with the stopper 27 or the end of the insertion tube portion 29 of the cylinder head 4.

In the first embodiment, as shown in FIG. 2, a taper 30 is formed on the end surface of the cushion ring 17 on the stopper 27 side. In addition, cushion hole 1
6 and the stopper 27 are continuous with the taper 30
Is formed. Therefore, if the cushion ring 17 is to be assembled in the reverse direction in the assembly process, the taper 3 of the cushion ring 17
The end face on the side where no 0 is formed hits the inclined surface 31.
In this case, since the cushion ring 17 protrudes from the cushion hole 16 toward the insertion hole 26, the insertion cylinder portion 29 cannot be completely inserted into the insertion hole 26, and the adjacent surface 3 of the cylinder head 4 cannot be inserted.
A gap is formed between the third surface 3 and the adjacent surface 35 of the retainer 3. Therefore, the worker can be made aware that the cushion ring 17 is turned in the opposite direction, and it is possible to prevent the assembling work from proceeding incorrectly.

Inserting the retainer 3 and the cylinder head 4 from the opening 1a of the cylinder tube 1,
As shown in FIG. 1, the outer peripheral surface of the cylinder head 4 is screwed and fixed to the inner peripheral surface of the opening 1a. In this state, a clearance is secured between the inner peripheral surface of the insertion tube portion 29 and the rod 2 to form the flow path 11. And, this channel 11
Are connected to a port 13 via a communication passage 12 formed in the cylinder head 4. Also, in this state,
The flange 28 of the retainer 3 is connected to the cylinder tube 1
It is configured to be pressed against the step portion 24 inside. In addition,
Since the cushioning effect when the rod 2 makes a stroke is the same as that of the above-described conventional example, the description thereof is omitted here.

In the cylinder device of the first embodiment described above, when the cushion ring 17 is incorporated into the cushion hole 16, the cushion ring 17 may be inserted from the insertion hole 26 side, so that the stopper 27 is integrated with the retainer 3. Can be formed beforehand. Further, an insertion cylinder portion 29 to be inserted into the insertion hole 26 is formed integrally with the cylinder head 4. Since the cylinder head 4 is firmly fixed to the cylinder tube 1, even if the cushion ring 17 abuts on the insertion tube portion 29, the insertion tube portion 29 does not shift. Therefore, the stop ring 18 and the snap ring 1
9 can be eliminated, the number of parts can be reduced, and the cost can be reduced.

In the first embodiment, when the cylinder head 4 is fixed, the flange 28 of the retainer 3 is pressed against the step portion 24 in the cylinder tube 1, and the portion functions as a seal. Therefore, as shown in FIG. 1, even if the O-ring 14 is not provided on the retainer 3 side, the leak between the port 13 and the pressure chamber 36 can be prevented, and the cost can be reduced by reducing the number of parts. be able to.

When the flange 28 is pressed against the step portion 24, the movement of the retainer 3 is controlled by the cylinder head 4 toward the opening 1a of the cylinder tube 1.
The piston 25 is regulated by the step portion 24 and the flange 28, respectively. Therefore, it is possible to prevent the retainer 3 from rattling without using the connecting member 7 and the ring 8 as in the above-described conventional example, to reduce the number of parts, simplify the assembly, and reduce the cost. Can be.

The cylinder device of the second embodiment shown in FIG.
This embodiment is different from the first embodiment in that the shapes of the retainer 3 and the cylinder head 4 are changed. Therefore, only the differences will be described below. The inner peripheral surface of the retainer 3
Rather than having different diameters as in the first embodiment, a constant diameter is provided. However, this retainer 3
It is the same that the stopper 27 is integrally formed on the inner peripheral surface.

A ring-shaped cushion ring 1 made of metal or synthetic resin is provided on the inner peripheral surface of the retainer 3.
After assembling, the cylindrical member 32 is pressed into the inner peripheral surface. Therefore, here, the portion of the inner peripheral surface of the retainer 3 sandwiched between the stopper portion 27 and the tubular member 32 forms the cushion hole 16, and the portion into which the tubular member 32 is inserted forms the insertion hole 26. . The cushion ring 17 thus configured is allowed to move in the axial direction until it comes into contact with the stopper 27 or the end of the tubular member 32.

On the other hand, the insertion cylinder portion 29 is not formed on the adjacent surface 33 of the cylinder head 4 on the retainer 3 side, and is kept flat. A communication groove 34 is formed in the radial direction of the adjacent surface 33.

Also in the second embodiment, the retainer 3 and the cylinder head 4 are inserted through the opening 1a of the cylinder tube 1, and the outer peripheral surface of the cylinder head 4 is moved to the inner periphery of the opening 1a as shown in FIG. Screw it to the surface and fix it. And, a clearance is secured between the inner peripheral surface of the cylindrical member 32 and the rod 2 to form the flow path 11. Here, in the second embodiment, the communication groove 34 formed in the adjacent surface 33 of the cylinder head 4 and the adjacent surface 35 of the retainer 3 are combined to form the communication passage 12. And
The flow path 11 is connected to the port 1 through the communication passage 12.
It is connected to 3.

In the second embodiment described above, similarly to the first embodiment, when the cushion ring 17 is installed in the cushion hole 16, the cushion ring 17 is inserted into the insertion hole 26.
The stopper 27 can be inserted from the side of the retainer 3.
Can be integrally molded. Also, the insertion hole 26
The cylinder member 32 inserted into the cylinder head 4 is a separate member, but its end portion is in contact with the adjacent surface 33 of the cylinder head 4.
Since the cylinder head 4 is firmly fixed to the cylinder tube 1, the cushion ring 17
Does not shift even when the cylinder member 32 comes into contact with the cylinder member 32. Therefore, unlike the above-described conventional example, it is not necessary to use the snap ring 19, and the number of parts can be reduced, and the cost can be reduced.

Further, in the second embodiment, the cylindrical member 32
Is a separate member, but since the insertion tube portion 29 is not integrally formed with the cylinder head 4 as in the first embodiment, the adjacent surface 33 of the cylinder head 4 and the adjacent surface 35 of the retainer 3 are not formed.
Can be adjacent to each other while being flat. Therefore, if the communication groove 34 is formed in either of the adjacent surfaces 33 and 35, the communication passage 12 can be formed without performing a drilling process. Of course, similarly to the above-described first embodiment, the step portion 24 and the flange 28 work together to exhibit a sealing function, and the play of the retainer 3 can be prevented without using the connecting member 7 and the ring 8.

The insertion tube portion 29 and the tube member 32 in the first and second embodiments constitute a tube member in the present invention. Further, the diameter of the insertion tube portion 29 and the insertion hole 26 into which the tube member 32 is inserted may be at least larger than the diameter of the cushion ring 17 in consideration of incorporating the cushion ring 17. For example, if the inner peripheral surface of the retainer 3 has a constant diameter as in the second embodiment, the effect that the processing can be simplified can be obtained. Further, in the first and second embodiments, the rod 2
Although the description has been made using the rod chamber side type cylinder head 4 through which the rod 2 penetrates, a bottom side type cylinder head through which the rod 2 does not penetrate may be used.

[0034]

According to the first aspect of the present invention, when the cushion ring is inserted into the cushion hole, the cushion ring may be inserted from the insertion hole side, so that the stopper 27 is formed integrally with the retainer 3. Can be. Also,
Since the cylinder member inserted into the insertion hole is linked to the cylinder head which is firmly fixed, the cylinder member does not shift even if the cushion ring contacts the cylinder member. Therefore, unlike the above-described conventional example, a snap ring is not required separately from the stop ring, and the number of parts can be reduced and cost can be reduced.

According to the second aspect, in the first aspect, since the cylindrical member is formed integrally with the cylinder head, the number of parts can be further reduced. According to the third invention, in the first invention, although the cylindrical member is a separate member, the adjacent surface of the cylinder head and the adjacent surface of the retainer can be made flat and adjacent to each other. Therefore,
If a communication groove is formed on any of the adjacent surfaces, a communication passage can be formed without performing a boring process.

According to the fourth invention, in the first to third inventions, the flange of the retainer is pressed against the step in the cylinder tube, and the sealing function is exerted at that portion.
Therefore, it is not necessary to provide the O-ring on the retainer side, and the cost can be reduced by reducing the number of parts. In addition, when the flange is pressed against the step, the movement of the retainer is regulated by the cylinder head toward the opening of the cylinder tube and by the step and the flange toward the piston. Therefore, it is possible to prevent rattling of the retainer without using the connecting member and the ring as in the above-described conventional example, to reduce the number of parts, simplify the assembly, and reduce the cost.

According to the fifth invention, in the first to fourth inventions, if the cushion ring is to be assembled in the reverse direction in the assembling step, the end surface of the cushion ring on which the taper is not formed is inclined. Bump into Therefore, even if you try to assemble other parts, it will not be able to assemble properly, so that the worker can notice that the cushion ring is in the opposite direction, and it is possible to prevent the assembly work from proceeding incorrectly it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a cylinder device according to a first embodiment.

FIG. 2 is a perspective view showing a cushion ring 17;

FIG. 3 is a sectional view showing a cylinder device according to a second embodiment.

FIG. 4 is a sectional view showing a conventional cylinder device. It is to be noted that the type shown in FIGS.

FIG. 5 is a perspective view showing a ring-shaped connecting member 7 and a ring 8;

FIG. 6 is a view showing an end surface of the cushion ring 17 on the stop ring 18 side.

[Explanation of symbols]

 Reference Signs List 1 cylinder tube 1a opening 2 rod 3 retainer 4 cylinder head 11 flow path 12 communication passage 13 port 16 cushion hole 17 cushion ring 21 relay groove 22 cushion bearing 24 step 25 piston 26 insertion hole 27 stopper 28 flange 29 insertion cylinder 30 Taper 31 Inclined surface 32 Tube member 33 Adjacent surface (of cylinder head 4) 34 Communication groove 35 Adjacent surface (of retainer 3) 36 Pressure chamber

Claims (5)

[Claims] 1. A cylinder tube, a rod incorporated in the cylinder tube, a piston provided in the rod, a cylindrical retainer that forms a pressure chamber in the cylinder tube together with the piston, and a cylinder tube adjacent to the retainer. A cylinder head attached to the end, a cushion hole formed on the inner peripheral surface of the retainer on the pressure chamber side, a cushion ring incorporated in the cushion hole so as to be movable in the axial direction, and a cylinder head closer to the cushion hole on the inner peripheral surface of the retainer. And an insertion hole having a diameter larger than at least the cushion ring, a stopper formed at the pressure chamber side opening of the cushion hole while being formed integrally with the retainer, and inserted into the insertion hole and linked to the cylinder head. Formed in the radial direction of the cylinder member and the stopper-side end surface of the cushion ring. A joint groove, a port formed in the cylinder tube, and a communication passage that communicates the port with a flow path on the inner peripheral surface of the cylindrical member, the rod is stroked, and a predetermined position of the rod is located on the inner peripheral surface of the cushion ring. When inserted,
A throttle effect is exerted between the predetermined position of the rod and the inner peripheral surface of the cushion ring, and the cushion ring is configured to move in the axial direction within a range until it comes into contact with the stopper or the end of the cylindrical member. Cylinder device. 2. The cylinder device according to claim 1, wherein the cylinder member is formed integrally with the cylinder head. And a connecting groove formed on an adjacent surface of one of the retainer and the cylinder head. When the retainer and the cylinder head are adjacent to each other, the connecting groove includes: 2. The cylinder device according to claim 1, wherein the other adjacent surface of the retainer and the cylinder head is combined to form a communication passage connecting the port to the flow path. 4. An opening formed by enlarging the inner peripheral end of the cylinder tube, a step formed in the cylinder tube by the inner bottom surface of the opening, and a flange provided on the outer peripheral surface of the retainer. Wherein when the cylinder head is inserted into the opening and fixed at a predetermined position, the flange of the retainer is configured to be pressed against a step in the cylinder tube. A cylinder device according to any one of the preceding claims. 5. A taper formed on one end surface of a cushion ring, and an inclined surface formed on one of a stopper side and an end portion side of a cylindrical member so as to correspond to the taper of the cushion ring. Claim 1 characterized by the following:
The cylinder device according to any one of claims 1 to 4.