JPS6033446Y2 - Pilot pressure regulating valve for pressure control valve equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a pilot pressure regulating valve used in a pressure control valve device that controls the supply pressure of a working fluid (hereinafter referred to as hydraulic oil).

Conventionally, as a means for controlling the supply pressure of hydraulic oil to a hydraulic actuator, a relief valve that responds to the supply pressure is provided on the supply side of a hydraulic pump, but this type of IJ IJ-
The valve applies the supply pressure of hydraulic oil directly to the valve body, resisting the spring force (equipped with a set corresponding to the supply pressure to the operating part) that biases the valve body in the valve closing direction. Since the structure was such that the valve was opened, when the hydraulic oil was relieved, it flowed while pushing the valve body open.Also, due to the flow path resistance due to the small valve opening, the kinetic energy of the hydraulic oil was converted into thermal energy. This caused the oil temperature to rise.

Therefore, a pressure control valve is provided in which a pilot oil passage is provided, the operation of the relief valve is controlled by the pilot oil passage, and the spring set that biases the relief valve element in the valve closing direction can be made extremely weak. However, the pilot valve in the pilot oil passage formed in the pressure control valve needs to change the pilot ratio (expressed as the fluctuation range of the supply pressure to the operating part) in accordance with the requirements of the operating part. The entire pilot valve had to be changed.

The present invention provides a pressure control valve device having a pilot oil passage in which the pilot valve is divided into two parts and the pilot ratio can be changed by changing the valve body and valve seat of one side. Let's explain based on an example.

In FIG. 1, 1 is a tank, 2 is a hydraulic pump, and a hydraulic oil supply passage 3 is connected to the discharge side of the hydraulic pump 2.
is connected to a hydraulic cylinder 6, which is an operating section, via a one-way valve 4 and a switching valve 5, and the hydraulic cylinder 6 is activated and stopped by appropriately operating the switching valve 5.

7 is an accumulator.

A pressure control valve device 8 according to the present invention is provided to maintain the supply pressure of the hydraulic oil supply passage 3 at a predetermined value.

This pressure control valve device 8 will be explained with reference to FIGS. 2, 3, and 4. In the figures, P indicates an input port communicating with the discharge side of the hydraulic pump 2, and A indicates the operation of the switching valve 5, etc. R is a relief port that communicates with the tank 1, and the input port P and the output port A communicate with each other through a hydraulic oil supply passage 3 in the valve body 10. A one-way valve 4 is interposed.

41 is a valve seat, 42 is a valve body, and 43 is a spring.

Further, the input port P and the relief port R are communicated through a relief passage 11 in the valve body 10, and a first on-off valve 12, which is a relief valve, is interposed in the middle of the relief passage 11.

13 is a valve seat of the first on-off valve 12; 14 is a valve body; this valve body 14 is biased in the closing direction by a spring 15; The opening operation is performed by increasing the differential pressure between the oil pressure and the oil pressure in the chamber 16 behind the valve body 14, which is guided through an orifice 30 formed in the valve body 14.

The chamber 16 is connected to the valve body 10' through an orifice 17.
The relief passage 11 is connected to the downstream side of the first on-off valve 12 by a communication passage 18 which is a pilot oil passage formed in the relief passage 11, and a second on-off valve 19 which is a pilot valve is interposed in the middle of the communication passage 18. There is.

20a is a control valve seat of the second on-off valve 19, and 21a is a control valve body, and this control valve body 21a is urged in the closing direction by a spring 23 having an adjustment mechanism 22 via the spring seat 23a.

The operating valve seat) 20b is in contact with the control valve seat) 20a.
An operating valve 21b is provided in the operating valve seat 20b in a freely displaceable and oil-tight manner, and the amount of displacement of the operating valve body 21b is limited by a portion 21c.

The control valve body 21a and the control valve seat 20a are loosely fitted together, and the hydraulic oil in the passage 18 acts on the operating valve body 21b.

The hydraulic pressure downstream of the one-way valve 4 of the hydraulic oil supply passage 3 is supplied to the chamber 2 formed in the blind lid 20c by the hydraulic pressure introduction passages 24, 25, and 26.
7 and while the control valve body 21a is closed, the pressure in the hydraulic pressure introduction passages 24, 25, 26 and the chamber 27 is lower than the pressure in the passage 18 due to a pressure loss caused by the setting of the spring 43 of the one-way valve 4. The pressure decreases slightly, and the operating valve body 21b is located at the right end due to the pressure difference between the communication passage 18 and the chamber 27.

The pressure receiving area of the operating valve body 21b is larger than the pressure receiving area of the control valve 21, and the outer peripheral portion of the control valve seat 20a is connected to the operating valve seat 2.
An O-ring 19a is disposed in a triangular annular groove 20d formed in the corresponding portion with 0b to block communication between the chamber 27 and the passage 18 side.

Next, the action will be explained.

The oil pressure in the hydraulic oil supply passage 3 increases and the control valve 19 in the passage 18
When the product (PiS□) of the pressure on the more upstream side (P□) and the pressure receiving area (S□) of the control valve body 21a becomes larger than the set force (F) of the spring 23 (PtSz>F), the second on-off valve 19
The control valve body 21a moves to the left in the figure.

Then, the hydraulic oil in the chamber 16 behind the valve body 14 of the first on-off valve 12 flows from the communication passage 18 to the downstream of the first on-off valve 12 in the IJ-F passage 11, and the oil pressure in the chamber 16 decreases, causing the valve to close. body 14
A pressure difference is generated before and after the orifice 30 formed in the .

As a result, this differential pressure causes the valve body 14 of the first on-off valve 12 to move upward in the figure and open the valve, causing a portion of the hydraulic oil supplied by the hydraulic oil supply passage 3 to be relieved by the relief passage 11.

Due to relief, the oil pressure in the communication passage 18 decreases to almost atmospheric pressure, so the pressure P2 on the downstream side of the one-way valve 4
The operating valve body 21b moves to the left due to the pressure (P2) in the chamber 27 and continues to displace the control valve body 21a against the set force (F) of the spring 23 (the pressure receiving area of the operating valve 21b is defined as S2). Then, P2S2 > F).

Therefore, the pressure on the operating part side (output capo) A) becomes the pressure necessary for operation, and the oil pressure on the input port side becomes approximately atmospheric pressure (the set pressure of the spring 15).

The pressure on the output port side continues to decrease (due to operation) in chamber 2.
7 (P2) and the pressure receiving area (S2) of the operating valve body 21b
) and the product (P2S2) is the setting force of the spring 23 (F
) or less (P2S2<F), the control valve body 21a closes, the differential pressure across the orifice 30 disappears, and the first on-off valve 12 closes.

When the first on-off valve 12 closes, the oil pressure on the input port side rises, opens the one-way valve 4, and is guided to the output port A.

When the pressure at output port A increases, the operation is repeated as described above.

The supply pressure is controlled in this way. With such a pressure control valve device 8, when the supply pressure fluctuates, the first opening/closing valve 19 is controlled based on the opening/closing operation of the second opening/closing valve 19 that responds to the pressure. The oil pressure in the chamber 16 that acts on the valve body 14 of the first on-off valve 12 is changed, even if the pressure change upstream of the one-way valve 4 of the hydraulic oil supply passage 3 that acts on the valve body 14 of the first on-off valve 12 is small. Since this is amplified and transmitted to the valve body 14, the loss of kinetic energy of the hydraulic oil flowing by pushing the valve body 14 open is extremely small, so that the oil temperature does not rise.

The orifice 17 is provided to prevent the valve body 14 of the first on-off valve 12 from hunting due to a sudden drop in the oil pressure in the chamber 16 when the second on-off valve 19 opens.

In the above operation, the opening pressure (Pl) of the control valve body 21a
The ratio (P2/Pt) between this and the closing pressure (P2) is called the pilot ratio, and this ratio, that is, the pressure fluctuation, must match the requirements of the equipment connected to the output port A.

As explained above, according to the pressure control valve device according to the present invention, the loss of kinetic energy of the hydraulic oil during relief is small, and it can be suitably used without being accompanied by a rise in oil temperature.

Furthermore, the second on-off valve 19 provided in the communication passage 18 is divided into two parts, so that only the valve (operating valve) that receives the pressure downstream of the one-way valve (eight output ports) can be changed.
An arbitrary pilot ratio can be easily selected by preparing several types of operation valves without requiring many types of second on-off valves themselves.

Moreover, with just one O-ring 19a, it is possible to maintain oil tightness between the chamber 27 and the communication passage 18, as well as between the chamber 27 and the operating valve body 21b on the communication passage 18 side, where pressure is applied, improving assembly ease and making it practically effective. It is an idea.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram including a pressure control valve device according to the present invention, Fig. 2 is a detailed sectional view of the same device, Fig. 3 is an enlarged sectional view of the main part of Fig. 2, and Fig. 4 is a diagram of the same device. FIG. 3 is a diagram illustrating operating characteristics. 3...Hydraulic oil supply passage, 4...One-way valve, 11...Relief passage, 12...
First on-off valve, 30... Orifice, 16...
...Chamber, 18...Communication passage, 19...
Second on-off valve.

Claims (1)

[Scope of utility model registration request] IJ I branched from upstream of the one-way valve installed in the working fluid supply passage from the fluid pressure pump to the fluid pressure actuator.
)-7 passage is interposed with a first opening/closing valve operated by the differential pressure between the fluid pressure upstream of the one-way valve and the fluid pressure in the chamber into which the fluid pressure is introduced via the orifice, while
- communicating the first opening/closing valve downstream of the fu passage through a communication passage;
In a pressure control valve device in which a second on-off valve operated by fluid pressure downstream of the one-way valve is interposed in the communication passage, the second on-off valve is divided into two parts, one of which is a control valve for opening and closing the communication passage;
A pilot pressure regulating valve for a pressure control valve device, characterized in that the other is an operating valve that controls opening and closing of the control valve by fluid pressure on the downstream side of the one-way valve.