JP2002339912A - Reciprocating piston device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reciprocating piston device having superior practicality and generality and capable of arbitrarily providing the maximum generated load and the maximum generated speed exhibited by a piston by arbitrarily setting a pressure receiving area of a pressure receiving part of the piston. SOLUTION: The piston 3 comprises the pressure receiving part 5 receiving a hydraulic pressure in a cylinder hole 2 and shaft parts 6a and 6b provided on the both sides of the pressure receiving part 5. At least one of the shaft parts 6a and 6b is fitted with a sleeve 7a sliding relative to a cylinder 1 by integrated with the shaft part 6a or a sliding relative to the shaft part 6 by integrated with the cylinder 1. The sleeve 7a is provided with a restriction part 8a abutting on the pressure receiving surface 5a of the pressure receiving part 5 and making the pressure receiving area of the pressure receiving part 5 to a small area in the case where the sleeve 7a slides on the cylinder 1 by integrated with the shaft part 6a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A reciprocating piston device in which a piston reciprocates by hydraulic control has been proposed as a servo actuator of a vibration test device.

FIG. 1 shows a conventional example of this reciprocating piston device.

In this conventional example, a cylinder 31 and the cylinder 31
Pressure receiving part 35 slidably fitted in cylinder hole 32 in 31
A pump 33 and a servo valve 36 for pouring oil into and out of the cylinder hole 32 to reciprocate the piston 33, and by switching the servo valve 36 while driving the pump 34, The piston 33 is caused to reciprocate by arbitrarily pouring oil into and out of the cylinder hole 32 and alternately pressurizing the pressure receiving portion 35 from the left and right (actually, the difference between the left and right of the pressure receiving portion 35). The pressure is applied by pressure.)

The conventional example has the following problems.

The maximum generated load (Fmax) and the maximum generated speed (Vmax) when the piston 33 reciprocates are determined by the pressure receiving portion.
It is greatly affected by the pressure receiving area S of 35. That is, the maximum generated load and the maximum generated speed are determined by the following equations.

Fmax = Pmax × S, Vmax = Qmax / S, where Pmax = maximum pressure of the oil acting on the cylinder hole 32 Qmax = maximum flow rate of the oil flowing into and out of the cylinder hole 32

Therefore, in the conventional example, since the pressure receiving area S of the pressure receiving portion 35 is constant, the maximum generated load and the maximum generated speed are reduced.
It is determined by the performance of the servo valve 36 and the performance of the servo valve 36, and the piston 33 can be reciprocated only at the load up to the maximum generation load and the speed up to the maximum generation speed, and there is a problem that versatility is poor. .

The present invention solves the above problems,
It is intended to provide a reciprocating piston device excellent in practicability and versatility that can arbitrarily realize the maximum generated load and the maximum generated speed that the piston can exert by setting the pressure receiving area of the pressure receiving portion of the piston arbitrarily. is there.

[0010]

The gist of the present invention will be described with reference to the accompanying drawings.

[0011] A cylinder 1, a piston 3 slidably fitted in a cylinder hole 2 in the cylinder 1, and a fluid injecting / injecting device for injecting a fluid into the cylinder hole 2 and reciprocating the piston 3. 4, wherein the piston 3 comprises a pressure receiving portion 5 that receives fluid pressure in the cylinder hole 2, and shaft portions 6 a and 6 b provided on both sides of the pressure receiving portion 5. The shafts 6a and 6b
A sleeve 7a that slides integrally with the shaft 6a on the cylinder 1 or slides integrally with the cylinder 1 on the shaft 6a is fitted on at least one of the sleeves 7a. In a situation where the sleeve 7a slides with respect to the cylinder 1 integrally with the shaft portion 6a, the limiting portion 8a abuts against the pressure receiving surface 5a of the pressure receiving portion 5 to reduce the pressure receiving area of the pressure receiving portion 5 to a small area. Provided in the reciprocating piston device.

The reciprocating piston device according to claim 1, wherein sleeves 7a and 7b are fitted on both shaft portions 6a and 6b provided on both sides of the pressure receiving portion 5. It is related.

Further, in the reciprocating piston device according to any one of claims 1 and 2, when the sleeve 7a is integrated with the shaft portion 6a, the first blocking body 9a is fixed to the end of the shaft portion 6a. The sleeve 7a is configured so as not to slide with respect to the shaft portion 6a. In a situation where the sleeve 7a is integrated with the cylinder 1, a second blocking body 10a is fixed to the end of the sleeve 7a. The reciprocating piston device is characterized in that the sleeve 7a is configured not to slide with respect to the cylinder 1.

Further, in the reciprocating piston device according to the third aspect, the first blocking member 9a and the second blocking member 10a are provided detachably, respectively, according to the reciprocating piston device.

Further, in the reciprocating piston device according to any one of claims 3 and 4, a cylindrical one is employed as the cylinder 1, and ring portions 11a are provided at both ends of the inner surface of the cylinder 1.
11b are provided respectively, and at the end of the sleeve 7a on the pressure receiving portion 5 side, a protruding flange 15a is provided to protrude outward, and the second blocking body 10a is fixed to the end of the sleeve 7a. In this situation, the cylinder 1 and the sleeve 7a are configured to be integrated with each other by sandwiching the ring portion 11a between the fixed second blocking body 10a and the protruding flange 15a. It relates to a reciprocating piston device.

Further, in the reciprocating piston device according to any one of claims 3 to 5, the first blocking member 9a is provided with a shaft portion 6a.
In a situation where the shaft 7a and the sleeve 7a are integrally formed, the sleeve 7a is sandwiched by the first blocking body 9a and the pressure receiving portion 5 which are fixed to the end of the shaft 7a. It relates to a reciprocating piston device characterized by the following.

Further, in the reciprocating piston device according to any one of claims 1 to 6, the fluid injection / injection device 4 may include:
A reciprocating piston device comprising a fluid injection / injection device 4 including a pump 16 and a switching device 17 for switching injection / inflow of fluid discharged from the pump 16 into / from the cylinder hole 2. It is.

The reciprocating piston device according to any one of claims 1 to 7, wherein the reciprocating piston device is a servo actuator.

[0019]

When the restricting portion 8a of the sleeve 7a is brought into contact with the pressure receiving portion 5, the pressure receiving area of the pressure receiving portion 5 is reduced by the contact of the restricting portion 8a. The maximum generated load exerted by the piston 3 is reduced and the maximum generation speed is increased as compared with the case where the contact is not performed.

Since the present invention is configured as described above, it is excellent in practicability and versatility that can arbitrarily realize the maximum generated load and the maximum generated speed that can be exerted by the piston simply by changing the use of the sleeve. It becomes a reciprocating piston device.

[0021]

2 and 3 show one embodiment of the present invention, which will be described below.

In this embodiment, the cylinder 1 and the cylinder 1
Piston 3 slidably fitted in cylinder hole 2 in the inside
And a fluid injection / injection device 4 for injecting / injecting fluid into / from the cylinder hole 2 and reciprocating the piston 3, wherein the piston 3 receives a fluid pressure in the cylinder hole 2. It comprises a pressure receiving portion 5 and shaft portions 6a and 6b provided on both sides of the pressure receiving portion 5. At least one of the shaft portions 6a and 6b slides with respect to the cylinder 1 integrally with the shaft portion 6a. The sleeve 7a that moves or is integrated with the cylinder 1 and slides on the shaft 6a is fitted onto the sleeve 7a, and the sleeve 7a is integrated with the shaft 6a and slides on the cylinder 1 The pressure receiving portion 5 abuts against the pressure receiving surface 5a of the pressure receiving portion 5.
Is provided with a restricting portion 8a for reducing the pressure receiving area of the above.

The cylinder 1 has a cylindrical shape, and is provided with rings 11a and 11b at both ends of the inner surface of the cylinder 1. The shafts 6a and 6b of the piston 3 are connected to the rings.
It protrudes outward from 11a and 11b.

A first fluid inlet 12a for injecting fluid into one of the pressure receiving surfaces 5a of the pressure receiving portion 5 (the right side of the pressure receiving portion 5 in the drawing) is provided in the cylinder hole 2, and the other pressure receiving surface of the pressure receiving portion 5 is provided. A second fluid injection port 12b for injecting a fluid is provided on the 5b side (the left side of the pressure receiving unit 5 in the figure).

The fluid injecting / injecting device 4 includes a pump 16 and a switching device 17 for injecting a fluid discharged from the pump 16 into the first fluid inlet 12a or the second fluid inlet 12b, specifically, a servo valve. It is composed of

The pump 16 is connected to a tank 18 for storing the fluid.

The switching device 17 pressurizes the one pressure receiving surface 5a and the other pressure receiving surface 5b of the pressure receiving portion 5 with the fluid, and generates a pressure difference between the left pressure and the right pressure. The piston 3 is reciprocated by pushing the pressure receiving portion from the left side or the right side, and alternately generating the pushing from the left and the pushing from the right.

The piston 3 has both ends (shafts 6a and 6b).
Is projected from the cylinder hole 2, and at least one of the projections, the projection 19 on the left side in the drawing, is connected to a vibration generator or the like of a vibration test device. In addition, the drawing
This is a case where a connecting screw portion 20 is provided on 19.

In the figure, reference numeral 23 denotes a packing for preventing leakage of the fluid injected into the cylinder hole 2.

As the sleeves 7a and 7b, cylindrical bodies having a circular shape in cross section, which are fitted to the shaft portions 6a and 6b, are employed.
The cross-sectional shape may be a shape other than a circle, such as a square.

The pressure receiving portion 5 of the sleeves 7a and 7b
The side end surface is set to the restriction portions 8a and 8b. Also,
The drawing shows a protruding flange that protrudes outward from the edge on the pressure receiving portion 5 side.
15a and 15b are provided. This protruding collar 15a
15b has an effect of preventing the sleeves 7a and 7b from coming out of the cylinder hole 2, and also has the ring portions 11a and 11b of the cylinder 1 held together with the second blocking bodies 10a and 10b to be described later. It exerts the effect of being integrated. Since the protruding flanges 15a and 15b have end faces on the side opposite to the pressure receiving portion 5, the end surfaces of the protruding flanges 15a and 15b on the pressure receiving portion 5 side are not limited.

A state in which the sleeves 7a and 7b slide with respect to the cylinder 1 integrally with the shaft portions 6a and 6b (hereinafter, referred to as a first operating state), and the sleeves 7a and 7b are integrated with the cylinder 1; This integrated sleeve 7a
Switching between a state in which the shaft portions 6a and 6b slide with respect to the cylinder 7b and the cylinder 1 (hereinafter, referred to as a second operation state) is performed by first detachable bodies provided detachably at ends of the shaft portions 6a and 6b, respectively. 9a and 9b and second blocking bodies 10a and 10b detachably provided at the ends of the sleeves 7a and 7b, respectively.

More specifically, the first blocking members 9a and 9b employ a threaded body that is fitted to the shafts 6a and 6b and that is screwed and fixed to the ends of the shafts 6a and 6b. In the drawing, reference numerals 21a and 21b denote first screwing portions to which the first blocking bodies 9a and 9b are screwed.

The first blocking members 9a and 9b are arranged such that the positions of the sleeves 7a and 7b are set at positions where the limiting portions 8a and 8b abut against the pressure receiving surfaces 5a and 5b of the pressure receiving portion 5, respectively.
6b, the sleeves 7a and 7b are held and fixed between the pressure receiving surfaces 5a and 5b and the first blocking bodies 9a and 9b. Therefore, the first blocking bodies 9a and 9b
Is screwed onto the shaft portions 6a and 6b, whereby the shaft portions 6a and 6b and the sleeves 7a and 7b are integrated.

The second blocking members 10a and 10b employ a threaded body that is fitted on the sleeves 7a and 7b and that is screwed to the ends of the sleeves 7a and 7b. In the figure,
Reference numerals 22a and 22b are second screwing portions to which the second blocking bodies 10a and 10b are screwed.

In the second blocking members 10a and 10b, the positions of the sleeves 7a and 7b are adjusted so that the protruding flanges 15a and 15b
The sleeves 7a and 7 in the state where they are locked to the
b, the projecting flanges 15a and 15b and the second blocking body
The ring portions 11a and 11b, that is, the cylinder 1 are clamped and fixed to the ring portions 10a and 10b. Therefore, the second blocking body
When the sleeves 10a and 10b are screwed to the sleeves 7a and 7b, the sleeves 7a and 7b and the cylinder 1 are integrated.

Therefore, when the second blocking members 10a and 10b are not screwed to the sleeves 7a and 7b, and only the first blocking members 9a and 9b are screwed to the shaft portions 6a and 6b, the shaft portions 6a and 6b and the sleeve are not screwed. 7a and 7b are integrally slid with respect to the cylinder 1, ie, a first operating state (see FIG. 2). On the other hand, the first blocking bodies 9a and 9b are screwed to the shafts 6a and 6b. And the second blocking bodies 10a and 10b are attached to the sleeves 7a and 7b.
In the scene where it is screwed in, the sleeves 7a and 7b and the cylinder 1
And the integrated sleeves 7a and 7b
Then, a state is reached in which the shaft portions 6a and 6b slide with respect to the cylinder 1, that is, a second operating state (see FIG. 3).

In the first operating state, the limiting portions 8a and 8
b reduces the pressure receiving area of the pressure receiving section 5 to a small area.
In the second operating state, the pressure receiving surfaces 5a and 5b of the pressure receiving portion 5
Are all exposed (a state of a pressure receiving area of 100%).

When the first operating state and the second operating state are compared, the pressure receiving unit 5 in the first operating state is different from the second operating state.
Is smaller, the fluid pressure acting on the piston 3 is smaller in the first operating state than in the second operating state, and the piston 3 is inevitably moved to the second operating state in the first operating state. The maximum generated load is smaller than in the operating state.

In the first operating state, the sleeve 7a
7b is inserted, the diameter of the cylinder hole 2 becomes smaller, and the volume of the cylinder hole 2 decreases accordingly.
When the flow rate of the fluid acting on the cylinder is constant, the fluid is injected into the cylinder hole 2 to the maximum pressurized state in a short time in the first operating state as compared with the second operating state. 3 is that the maximum generation speed is faster in the first operation state than in the second operation state.

As described above, in the present embodiment, the pressure receiving area of the pressure receiving portion 5 is arbitrarily changed by changing the positions of the sleeves 7a and 7b, that is, the area is arbitrarily reduced.
A reciprocating piston device with excellent practicality and versatility that can freely change the maximum generated load and the maximum generated speed.

In particular, the servo actuator is required to have a simple structure in order to shorten the pipeline between the servo valve and the cylinder bore 2 as much as possible to increase the response and to reduce the frequency of occurrence of a failure. However, the first embodiment realizes versatility in spite of its simple structure, and in this respect, it is also excellent in practicality.

Also, the position of the sleeves 7a and 7b can be fixed only by attaching and detaching the first blocking members 9a and 9b and the second blocking members 10a and 10b, so that the operability is excellent in this respect.

Further, the first blocking bodies 9a and 9b and the second blocking bodies
Since the attachment and detachment of the 10a and 10b is performed by a screwing structure, the fixed first stoppers 9a and 9b and the second stoppers 10a and 10b
It is hard to be displaced due to the reciprocating motion, etc., and in this respect, practicality and reliability are excellent.

For example, a configuration may be adopted in which the sleeve is provided only on one shaft portion (in this case, the pressure receiving surfaces of the pressure receiving portions are different between the left and right sides, and the piston pulsates). Further, the sleeves may be double-fitted, and the pressure receiving area may be reduced by only one sleeve, or the pressure receiving area may be further reduced by both sleeves.

[Brief description of the drawings]

FIG. 1 is an explanatory side sectional view of a conventional example.

FIG. 2 is an explanatory side sectional view of the present embodiment.

FIG. 3 is an explanatory side sectional view of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder 2 Cylinder hole 3 Piston 4 Fluid pouring / injecting device 5 Pressure receiving part 5a / 5b Pressure receiving surface 6a / 6b Shaft 7a / 7b Sleeve 8a Restriction 9a First obstruction 10a Second obstruction 11a / 11b Ring 15a Projecting flange 16 Pump 17 Switching device

Claims (8)

[Claims] A cylinder, a piston slidably fitted in a cylinder hole in the cylinder, and a fluid injecting / injecting device for injecting fluid into and out of the cylinder hole to reciprocate the piston. In a reciprocating piston device, the piston includes a pressure receiving portion that receives fluid pressure in the cylinder hole, and shaft portions provided on both sides of the pressure receiving portion, and at least one of the shaft portions has a shaft portion. A sleeve which slides integrally with the cylinder or slides integrally with the cylinder with respect to the shaft portion is fitted, and this sleeve is integrated with the shaft portion with respect to the cylinder. A reciprocating piston device, wherein in a sliding situation, a restricting portion is provided which comes into contact with the pressure receiving surface of the pressure receiving portion and reduces the pressure receiving area of the pressure receiving portion. 2. The reciprocating piston device according to claim 1, wherein sleeves are fitted on both shaft portions provided on both sides of the pressure receiving portion. 3. The reciprocating piston device according to claim 1, wherein a first blocking member is fixed to an end of the shaft portion when the sleeve is integrated with the shaft portion. Are arranged so that they cannot slide with respect to the shaft, and when the sleeve is integral with the cylinder, a second blocking body is fixed to the end of the sleeve, and the sleeve slides with respect to the cylinder. A reciprocating piston device configured to be immovable. 4. The reciprocating piston device according to claim 3, wherein the first blocking member and the second blocking member are provided detachably. 5. The reciprocating piston device according to claim 3, wherein a cylindrical cylinder is employed as a cylinder, ring portions are provided at both ends of an inner surface of the cylinder, and a pressure receiving sleeve is formed as a sleeve. A protruding flange protruding outward is provided on the edge on the part side, and when the second blocking body is fixed to the end of the sleeve, the fixed second blocking body and the protrusion A reciprocating piston device, wherein the cylinder and the sleeve are integrated with each other by sandwiching the ring by a flange. 6. The reciprocating piston device according to claim 3, wherein the first blocking member and the pressure receiving portion are fixed when the first blocking member is fixed to an end of the shaft portion. A reciprocating piston device characterized in that the shaft portion and the sleeve are configured to be integrated with each other by sandwiching the sleeve. 7. The reciprocating piston device according to claim 1, wherein a pump and a switching device for switching a fluid discharged from the pump into and out of a cylinder hole are provided as the fluid injecting / injecting device. A reciprocating piston device characterized by employing a fluid injection / injection device provided with: 8. The reciprocating piston device according to claim 1, wherein said reciprocating piston device is a servo actuator.