JP2001304441A - Valve structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the impulsive sound produced when a valve element of a check valve, abuts on a seat. SOLUTION: A cushioning material 10 is mounted on a part where the valve element 8 abuts on the seat member, 5 for buffering the impact caused by the abutment on the valve element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a valve structure provided in a hydraulic machine such as a hydraulic shovel.

[0002]

2. Description of the Related Art Generally, a hydraulic machine such as a hydraulic shovel is provided with various valves for controlling supply and discharge of hydraulic oil. For example, a return system circuit from a control valve of the hydraulic shovel to an oil tank is provided. A check valve for holding back pressure is provided to prevent cavitation of the motor when turning is stopped. The check valve moves to a closed position in which the oil flow path is closed by contacting the seat 5 in a liquid-tight manner and an open position in which the check valve is separated from the seat 5 and opens the oil flow path, as shown in FIG. 5, for example. Free disk type valve element 8
In this case, the valve element 8 is
Based on the pressure and flow rate of the oil supplied from the upstream side (the control valve 2 side), the valve moves between the closed position and the open position according to the override characteristics shown in FIG.

[0003]

In a check valve provided in a return system circuit of the hydraulic excavator, for example, when a turning operation lever is suddenly operated from a turning position to a stop position to stop turning, the control valve side. The amount of oil flowing from the check valve to the
As a result, the valve element moves from the open position to the closed position in accordance with the override characteristic. In this case, the valve element is slammed against the seat by the pressure on the downstream side, causing a problem that an impact sound is generated. In addition, not only the impact sound when the valve body comes into contact with the seat when the valve body moves to the closed position, but also the valve body at the open position comes into contact with a body-side fixing member such as a plug to open the valve body further in the open position direction. However, there is a problem that an impact sound is generated when the valve body comes into contact with the body-side fixing member, and the problem to be solved by the present invention is as follows. was there.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been created with the object of solving these problems. In a valve configured using a valve body that is movable between a closed position that closes a passage and an open position that is separated from a seat to open an oil flow path, a valve body is provided at a contact portion between the seat and the valve body. Is provided with a shock-absorbing member for shock-absorbing when it contacts. By doing so, the shock when the valve body comes into contact with the seat is buffered by the buffer member, and it is possible to avoid such a problem that an impact sound is generated. Further, the present invention is also capable of freely moving between a closed position in which the oil flow path is brought into contact with the seat to close the oil flow path, and an open position in which the oil flow path is opened apart from the seat and the oil flow path is opened. In a valve configured by using a valve body that is in contact with the fixing member and is restricted from moving in the further open position direction, a contact portion between the fixing member and the valve body may be used when the valve body comes into contact with the fixing member. A shock absorbing member for damping an impact is provided. By doing so, the shock when the valve body abuts on the valve body-side fixing member is buffered by the buffer member, so that it is possible to avoid a problem that an impact sound is generated.

[0005]

Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a check valve for holding a back pressure provided in a return system circuit from a control valve 2 of a hydraulic shovel to an oil tank 3.
The check valve 1 is housed in a valve case 4 having an inlet port 4a connected to the control valve 2 side and an outlet port 4b connected to the oil tank 3 side.

The check valve 1 includes a cylindrical seat member 5 fixed to the inner peripheral surface of the inlet port 4a, a valve pin 7 integrally supported on the seat member 5 through a connecting rib 6, It is constituted by using a disk-shaped valve body 8 supported by a valve pin 7 so as to be movable in the axial direction, a spring 9 for pressing the valve body 8 to a closed position described later, and the like.

The valve element 8 contacts the seat member 5 based on the flow rate and pressure of oil input from the control valve 2 to the inlet port 4a in accordance with the override characteristic shown in FIG. Is moved between a closed position for preventing oil flow and an open position for allowing oil flow from the inlet port 4a to the outlet port 4b away from the sheet member 5. Further, the flow of oil from the outlet side port 4b to the inlet side port 4a is blocked because the flow in this direction acts as a force pressing the valve body 8 toward the closed position.

Further, the seat member 5 is provided with a cushioning member 10 for cushioning an impact when the valve body 8 comes into contact with the valve body 8 at the closed position. In the present embodiment, the cushioning member 10 is an annular member made of a rubber elastic material. The cushioning member 10 is elastically deformed when the valve body 8 in the closed position is pressed against the valve body 8 so that the valve body 8 and the seat member 5 are deformed. Between them can be sealed in a liquid-tight manner. The cushioning member 10 is prevented from falling off by engaging the engagement protrusion 10a protruding from the cushioning member 10 with the engagement groove 5a recessed in the sheet member 5. It can be attached to.

In the embodiment configured as described above, the valve element 8 of the check valve 1 is in a closed position where it contacts the seat member 5 to prevent the flow of oil, In this case, the sheet member 5 has
A shock-absorbing member 10 for damping an impact when the valve body 8 comes into contact with the seat member 5 is attached. As a result, for example, when the turning operation lever is suddenly operated when the turning is stopped, the amount of oil flowing from the control valve 2 to the check valve 1 suddenly decreases, thereby moving the valve from the open position to the closed position. Even if the body 8 collides vigorously with the sheet member 5 due to the pressure on the downstream side, the impact will not
Therefore, it is possible to avoid such a problem that the sound is absorbed and an impact sound is generated.

The present invention is, of course, not limited to the above embodiment, and the buffer member 10 can be provided on the valve body 8 side. Further, as in the following second embodiment, in a valve configured such that the valve body in the open position abuts on the valve body-side fixing member to restrict further movement in the open position direction. May have a buffer member for buffering an impact when the valve body contacts the fixing member. That is, the second embodiment will be described with reference to FIG. 4. In FIG. 4, reference numeral 11 denotes a poppet-type valve incorporated in the drift reduction valve.
The valve is configured to be movable between a closed position where the oil flow path is closed by contacting the sheet 12 in a liquid-tight manner and an open position where the oil flow path is opened apart from the sheet 12. Body 11 is
A plug 14 fixed to the valve body 13 of the drift reduction valve (corresponding to the valve body side fixing member of the present invention,
The valve body-side fixing member abuts on a member fixed to the valve body like the plug or a fixing portion integrally formed with the valve body) to restrict further movement in the opening position direction. It has become so. In this structure, the plug 14 is provided with a buffer member 15 (for example, a rubber sheet) for buffering an impact when the valve body 11 comes into contact with a portion where the valve body 11 at the open position comes into contact. I have. Also in the second embodiment, the shock when the valve body 11 comes into contact with the plug 14 is absorbed by the cushioning member 15, causing a problem that an impact sound is generated. Can be avoided. In this case, the buffer member 15 can also be provided on the valve body 11 side.

[Brief description of the drawings]

FIG. 1 is a sectional view of a check valve.

FIG. 2 is a diagram illustrating an override characteristic of a check valve.

FIG. 3 is an enlarged view of a main part.

FIG. 4 is a sectional view showing a second embodiment.

FIG. 5 is a cross-sectional view of a check valve showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Check valve 5 Seat member 8 Valve body 10 Buffer member 11 Valve body 12 Seat 14 Plug 15 Buffer member

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akiyoshi Komine 1-11-5 Nishi-Kanagawa, Kanagawa-ku, Yokohama-shi, Kanagawa F-term (reference) in Yamashin Kogyo Co., Ltd. 3H052 AA01 BA33 CB19 CB23 CB34 EA16 3H058 AA03 BB27 BB35 CB19 CB24 CB32 EE03 3H059 AA01 BB28 BB38 CB20 CB28 CD05 EE01 FF03 3H066 AA01 BA32 BA33 EA36

Claims (2)

[Claims] 1. A valve body which is movable between a closed position where it abuts a sheet in a liquid-tight manner to close an oil flow path and an open position which is separated from the sheet and opens an oil flow path. In the valve, a valve member is provided at a contact portion between the seat and the valve body, the cushioning member being configured to buffer an impact when the valve body comes into contact with the valve body. 2. The valve body is movable between a closed position in which the oil flow path is closed by contacting the seat in a liquid-tight manner and an open position in which the oil flow path is opened apart from the seat. In a valve configured by using a valve body that is in contact with the fixing member and is restricted from moving in the further open position direction, a contact portion between the fixing member and the valve body may be used when the valve body comes into contact with the fixing member. A valve structure provided with a buffer member for buffering an impact.