JPS6343532Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electromagnetic pressure reducing valve that constitutes a pressure reducing circuit and is driven by a solenoid.

As a conventional electromagnetic pressure reducing valve, there is one shown in FIG. 1, for example.

This electromagnetic pressure reducing valve consists of a valve component 1 that constitutes a pressure reducing circuit and a solenoid component 2 that drives a spool 10 of this valve component 1, and is simply the valve component 1 connected to the solenoid component 2. It is.

However, since the valve component 1 is externally attached to the solenoid component 2 in this way,
There are disadvantages in that a space is required for the valve components, there is a limit to miniaturization, and the entire electromagnetic pressure reducing valve cannot be made into a cartridge.

This invention was made in view of the above points, and aims to reduce the size of the electromagnetic pressure reducing valve, use a cartridge, and save power.

Therefore, the electromagnetic pressure reducing valve according to this invention has a spool that is pressed and driven by the mover, and this spool is slidably inserted into the fixed core of the solenoid component that includes the solenoid coil, the fixed core, and the mover. A valve component consisting of a fixed part is housed and provided, and the fixed part is provided with an oil passage forming a plurality of ports which are switched and connected by a spool, and its secondary oil pressure is transmitted by a movable piece of the spool. An oil passage is formed that leads to the oil chamber on the side opposite to the side being pressed.

Hereinafter, embodiments of this invention will be described with reference to FIGS. 2 and 3 of the accompanying drawings.

First, in FIG. 2, this electromagnetic pressure reducing valve has a valve component 1 built into a solenoid component 2, and the solenoid component 2 is connected to a sub-plate 3.

That is, the solenoid component 2 is connected to the bobbin 21
A solenoid coil 23 is wound around the housing 22 and molded in the housing 22, and a fixed iron core 2 is fixed in a cylindrical core tube 24 fitted into the housing 22.
5 and a magnetic movable element 26 slidably fitted therein.

The fixed core 2 of this solenoid component 2
5, a large diameter hollow part 25a and a small diameter hollow part 25b are formed in the axial direction. A valve component 1 is housed therein, and includes a spool 12 that is slidably fitted into the spool 12 and has its left end passed through a small-diameter hollow portion 25b and pressed into contact with a movable element 26.

The sleeve 11 of the valve component 1 has oil passages forming a P port, a C port, and a T port, which are switched and connected by a spool 12, and a secondary hydraulic pressure discharged from the C port is connected to the sleeve 11 of the spool 12. Child 2
While forming an oil passage 15 forming an orifice leading to the oil chamber 13 on the side opposite to the side pressed by Oil passages 25c and 25d are formed which communicate with the.

The spool 12 is given a leftward movement by a compression spring 16 disposed within the oil chamber 13.

In addition, an oil passage 12a is formed in the spool 12 so that the oil in the left and right oil chambers 27 and 13 can move as the spool 12 moves, and a groove through which oil also flows in the direction of the outer circumferential axis of the mover 26 is formed. 26a is provided to reduce the resistance when the spool 12 and the mover 26 move.

Then, the solenoid component 2, in which the valve component 1 is housed within the fixed iron core 25, is attached to the O-ring 2.
8 is attached to the core tube 24 into the recess 3a of the sub-plate 3, the flange plate 4 is fixed to the sub-plate 3 with bolts 5, and the core tube 24 is fixed to the sub-plate 3. and is connected to the sub-plate 3.

Note that the core tube 24 of the solenoid component 2
Between the small diameter end 24b and the housing 22,
A sealing O-ring 29 is interposed.

Furthermore, an adjustment screw 8 with an O-ring 7 attached thereto is threaded through the push rod 6 into the small diameter end 24b of the core tube 24, and a compression spring 9 is inserted between the push rod 6 and the movable element 26. I am intervening.

A hydraulic circuit diagram of the electromagnetic pressure reducing valve constructed in this manner is shown in FIG.

Next, the operation of the embodiment configured as described above will be explained.

First, when power is supplied to the solenoid coil 23 of the solenoid component 2, the fixed iron core 25 and the movable element 26
are excited and attract each other, and the movable element 26 moves to the right.

As a result, the spool 12 is pressed by the movable element 26 and moves to the right against the restoring force of the compression spring 16, opening between the C port and the T port.
The state where the ports are closed changes to the state where the C port and T port are closed and the C port and P port are open, and as a result, the pressure at the P port is added to the C port, and the pressure at the _C port increases. do.

At this time, oil passage 1 forming an orifice at port C
Oil chamber 1 on the right side of spool 12 communicating through 5
3, a secondary hydraulic pressure that is the pressure reduction of the P port hydraulic pressure is introduced, and as the pressure of the C port increases, the force in the leftward direction on the spool 12 due to the secondary hydraulic pressure in the oil chamber 13 also increases. .

Therefore, the spool 12 stops at a position where the force in the rightward direction by the mover 26, the restoring force of the compression spring 16, and the feedback force in the leftward direction due to the hydraulic pressure in the oil chamber 13 are balanced.

Therefore, even if the pressure at the P port fluctuates, feedback is provided by the oil pressure in the oil chamber 13, so the pressure at the P port changes.
The primary oil pressure of the port is reduced, and the secondary oil pressure of the C port is held substantially constant.

In this case, when the final displacement amount (steady displacement amount) of the spool 12 is x and the current flowing through the solenoid coil 23 is i, the following relationship holds true: P _C =k ₁ ·x=k ₂ ·i. However, k ₁ and k ₂ are constants.

That is, the pressure P _C at the C port changes approximately in proportion to the voltage or current applied to the solenoid coil 23.

When operating this electromagnetic pressure reducing valve manually, by screwing in the adjusting screw 8 and moving the mover 26 to the right via the push rod 6 and compression spring 9, it operates in the same way as when driven by a solenoid. can be done. Note that this adjustment screw is also used for zero adjustment (positioning) of the spool 12.

In this way, this electromagnetic pressure reducing valve has the valve component housed within the fixed core of the solenoid component, so that no space is required for the valve component, making it compact.

In addition, the solenoid component housing the valve component can be used as a pilot control element for pressure, flow rate, and directional control valves, for example, and the pilot component can be shared for valves of different sizes to create a cartridge. It is possible.

Furthermore, with this structure in which the oil passage switching function is placed within the fixed core, the space occupied by the solenoid coil is large compared to the overall size of the valve.As a result, it is possible to increase the number of turns of the coil, and the core tube diameter Because the spool can be made larger, the spool can be driven with a smaller current, reducing power consumption (electromagnetic force is proportional to the current x number of turns and the diameter of the movable piece), making it suitable as a power-saving valve. becomes.

In the above embodiment, a sleeve separate from the fixed core is provided, and the spool is slidably inserted into this sleeve as the fixed part. However, the fixed core can be used as the fixed part without providing the sleeve. The spool may be slidably inserted, and in this case each oil passage may be formed within the fixed core.

In addition, in the above embodiment, an example was described in which an oil passage communicating the port of the sleeve with a port of the sub-plate was formed in the fixed core, but the oil passage was formed in the sleeve itself and the fixed iron core was It is also possible not to form a path.

As explained above, according to this invention, it is possible to downsize the electromagnetic pressure reducing valve, use a cartridge, and save power.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a conventional electromagnetic pressure reducing valve, FIG. 2 is a longitudinal sectional view showing an embodiment of this invention, and FIG. 3 is a hydraulic circuit diagram thereof. 1... Valve component, 2... Solenoid component, 3
...Subplate, 11...Sleeve (fixed part),
12...Spool, 23...Solenoid coil,
24... Core tube, 25... Fixed iron core, 26
...Movable element.

Claims (1)

[Scope of utility model registration request] A valve component comprising a spool that is pressed and driven by the mover, and a fixing part into which the spool is slidably inserted into a fixed core of a solenoid component that includes a solenoid coil, a fixed core, and a mover. The fixed part is provided with an oil passage forming a plurality of ports that are switched and connected by the spool, and its secondary oil pressure is provided on the side of the spool opposite to the side pressed by the movable element. An electromagnetic pressure reducing valve with an oil path leading to the oil chamber.