JPS6225763Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an electromagnetically controlled pressure reducing valve.

Conventional technology Conventionally, in a pressure reducing valve, a solenoid that can obtain a suction force proportional to the current value is used, and in order to set the output pressure of the fluid to a pressure proportional to the current value, the solenoid suction force, spring force, and A device in which the feedback pressure from the output port is balanced is known, for example, from Japanese Patent Publication No. 47-27850.

However, in the above-mentioned known pressure reducing valve,
Generally, the configuration is such that the fluid pressure is opposed to the pressure regulating spring, and therefore, the problem of pressure drop due to the spring constant cannot be avoided in the flow characteristics.

Problems to be Solved by the Invention The invention aims to directly counteract the suction force of a solenoid, which has no spring constant, with the fed-back secondary pressure, without counteracting the fluid pressure with the biasing force of the pressure regulating spring. The aim is to obtain a pressure reducing valve with improved output characteristics.

Means for Solving the Problems In order to achieve the above object, the electromagnetically controlled pressure reducing valve of the present invention has an opening amount between the ports in the valve body, which is equipped with a fluid supply port, an output port, and a relief port. A control valve body is provided, and this valve body is
The supply port is connected to a solenoid that operates in a range where the attraction force between the movable iron core and the fixed iron core is proportional to the amount of energization, and the feedback pressure from the output port is applied to the valve body to balance it. In the pressure reducing valve, the valve body is configured by a spool, the movable iron core of the solenoid is connected to the spool, and the movable iron core of the solenoid is connected to the spool, facing the end of the spool, and outputting the fluid supplied from the spool to the output port. It is constructed by providing a pressure chamber that communicates with the port to apply feedback pressure to the spool that counteracts the suction force of the movable core, and providing an auxiliary return spring to apply a return force to the movable core.

Function In the pressure reducing valve of the present invention having the above configuration,
When the solenoid is energized with the required amount of current, a constant suction force acts on the movable core regardless of its stroke, and this balances with the feedback pressure to the pressure chamber facing the end of the spool, causing the spool to move. A constant reduced pressure output is obtained at the output port according to the amount of current applied. Since the suction force of the solenoid is opposed to the feedback pressure, the output characteristics are improved without being affected by the spring constant unlike when the biasing force of the spring is opposed to the fluid pressure. Note that the auxiliary return spring has a weak biasing force for returning the spool when no current is applied, and does not have a particular effect on the output characteristics.

Effects of the Invention According to the present invention described above, a pressure reducing valve with good output characteristics can be obtained with an extremely simple structure.

Embodiment Hereinafter, the present invention will be explained in detail based on an illustrated embodiment. In the electromagnetic control pressure reducing valve shown in FIG.
Reference numeral 1 indicates a valve portion, and reference numeral 2 indicates a solenoid portion. A valve body 3 in the valve portion 1 includes a fluid supply port 4, an output port 5, and a relief port 6.
A sleeve 10 having a supply opening 7, an output opening 8, and a relief opening 9 communicating with each of the ports 4, 5, and 6 is disposed inside the sleeve 10, and inside the sleeve 10,
Opening and closing the supply opening 7 and the relief opening 9,
A spool 11 that controls the opening amount of the flow path between the supply port 4 and the output port 5 and the flow path between the output port 5 and the relief port 6 is slidably inserted.

The solenoid section 2 is constructed by connecting the shaft rod 12 at one end of the spool 11 to a movable iron core 15 that is attracted and driven by the fixed iron core 14 of the solenoid 13, and is arranged at the other end of the spool 11. The return mechanism utilizes the feedback pressure of the fluid output and the biasing force of the spring, and the pressure chamber 16 where the output port 5 and the end of the spool 11 face each other.
and a feedback path 17 bored in the valve body 3.
An auxiliary return spring 20 is compressed between a needle screw 18 screwed into the valve body 3 and a spring seat hole 19 formed in the spool 11.

In addition, in order to regulate the adsorption distance of the movable core 15 to the fixed core 14, a bush 21 is attached to the surface of the fixed core 14 facing the movable core 15,
As a result, the stroke of the movable core 15 is set within a range in which the attraction force against the fixed core 14 is approximately proportional to the amount of current supplied to the solenoid 13, and the attraction force corresponding to the amount of current supplied to the solenoid 13, the above-mentioned feedback pressure, and the auxiliary return spring are adjusted. By displacing the movable core 15 to a position where the urging force of the port 20 is balanced, the flow paths between the ports 4, 5, and 6 can be switched, and the opening amount can be controlled.

In addition, in the figure, 22 is a stopper that restricts the return position of the spool 11.

Next, the operation of the electromagnetically controlled pressure reducing valve having the above configuration will be explained.

FIG. 1 shows a state in which the solenoid 13 is de-energized, the spool 11 is pressed against the stopper 22 by the auxiliary return spring 20, the supply opening 7 is closed, and the output opening 8 and the relief opening 9 are open. Now, when the solenoid 13 is energized, the movable core 15 overcomes the urging force of the auxiliary spring 20 and is attracted to the fixed core 14, and depending on the amount of energization, the relief opening 9 is closed and the supply opening 7 is opened. Accompanying this, pressure fluid flows from the supply port 4 to the output port 5 and from the output port 5 to the pressure chamber 16 in the valve body 3 via the feedback path 17. Then, at a position where the fluid pressure acting on the end of the spool 11 and the urging force of the auxiliary return spring 20 and the suction force acting on the movable iron core 15 are balanced by this fluid pressure feedback.
The spool 11 stops. Therefore, even if the pressure at the output port 5 increases for some reason,
The accompanying increase in feedback pressure causes the spool 11 to move and the opening amount of the supply opening 7 to decrease, thereby returning the pressure at the output port 5 to the set pressure corresponding to the amount of energization. Furthermore, if the amount of current applied to the solenoid 13 is reduced while the output port 5 is maintained at the set pressure, the suction force acting on the movable iron core 15 will be reduced, so that the spool 11 will be pressed by the feedback pressure. Relief opening 9
opens, thereby releasing the fluid in the output port 5, and when the pressure in the output port 5 decreases to some extent, the spool 11 is pressed by the movable core 15, the relief opening 9 is closed, and the spool 1
1 is displaced to a new balance position. Of course, when the power supply to the solenoid 13 is stopped, the spool 11 returns to the original position shown in FIG. 1 by the biasing force of the auxiliary return spring 20.

FIG. 2 shows the relationship between the stroke of the movable core 15 and the attraction force using the current value to the solenoid 13 as a parameter. As shown in the figure, within the range l ₁ , the attraction force increases significantly as the movable core 15 approaches the fixed core 14, but within the range l ₂ , the attraction force increases regardless of the stroke. is approximately proportional to For this reason, the present invention utilizes the range of _l2 , and the bush 21 and stopper 22 set the stroke of the movable core 15 within the range of _l2 , where the attraction force is proportional to the amount of energization. .

Furthermore, Figure 3 shows the relationship between the current value of the solenoid 13 and the secondary pressure on the output port 5 side.As is clear from this, if the current value is changed, the output will be approximately proportional to the change. The pressure in port 5 can be varied. Note that the pressure characteristics of the output port 5 can be changed by rotating the needle screw 18 or replacing the auxiliary return spring 20.

In the above embodiment, the output port 5 and the pressure chamber 16 in the valve body 3 are communicated via the feedback path 17 bored in the valve body 3, but instead of this, as shown in FIG. Communication can also be made through a feedback hole 23 drilled in 11. The embodiment shown in FIG. 4 is substantially the same as the embodiment shown in FIG. 1 except for the above-mentioned points, so the same or corresponding parts are given the same reference numerals and the explanation thereof will be omitted.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the electromagnetically controlled pressure reducing valve according to the present invention, Fig. 2 is a diagram showing the suction characteristics of the solenoid, Fig. 3 is a diagram showing the characteristics of the output port pressure with respect to the current value of the solenoid, and Fig. 4 is a diagram showing the characteristics of the output port pressure with respect to the current value of the solenoid. The figure is a sectional view of another embodiment. 3... Valve body, 4... Supply port, 5... Output port, 11... Spool, 13... Solenoid, 14... Fixed iron core, 15... Movable iron core, 20
...Auxiliary return spring, 21...butt.

Claims (1)

[Scope of utility model registration request] A valve body that controls the opening amount between these ports is provided in the valve body equipped with a fluid supply port, an output port, and a relief port. Connected to a solenoid that operates in a range proportional to the amount of energization, the feedback pressure from the output port is applied to the valve body, and in a balanced state, the fluid supplied from the supply port is output to the output port at a reduced pressure. In the valve, the valve body is constituted by a spool, and the movable core of the solenoid is connected to the spool, and the movable core of the solenoid is connected to the end of the spool and communicated with the output port, so that the movable core is connected to the suction force of the movable core. An electromagnetically controlled pressure reducing valve, characterized in that it is provided with a pressure chamber that applies opposing feedback pressure to the spool, and is provided with an auxiliary return spring that applies a return force to the movable core.