JPS6319603Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention drives the main valve with pilot hydraulic pressure guided by a pilot valve driven by a solenoid, and adjusts the current value to flow through the solenoid. This invention relates to a proportional solenoid valve that controls the amount of oil flowing through a main valve.

[Conventional technology]

As a conventional proportional solenoid valve of this type, for example, the first
There is something like the one shown in the figure.

This proportional solenoid valve has a pilot valve component 2 and a solenoid component 3 for driving it arranged on both sides of a main valve part 1 (only the left half is shown in the figure).

The solenoid component 3 is connected to the bobbin 3.
A solenoid coil 32 is wound around 0 and molded in the housing 30, a fixed iron core 34 is fixed in a cylindrical core tube 33 fitted into the housing 31, and a magnetic mover 35 is installed inside so as to be able to slide slightly. Equipped with push pin 36
is fixed to the mover 35 and slidably penetrates the fixed iron core 34.

Solenoid coil 3 of this solenoid component 3
2, the fixed core 34 and the mover 35
are excited and attract each other, and the movable element 35 moves to the right along with the push pin 36.

As a result, the pilot spool 20 of the pilot valve component 2 moves to the right against the restoring force of the spring 22 disposed in the oil chamber 21, and the T and C ports shown in the figure are opened and the P and C ports are opened. is closed, T port and C port are closed, P port and C
The port is open.

As a result, the pilot hydraulic pressure is communicated to the C port, the pressure at the C port increases, and the main spool 10 of the main valve portion 1 moves to a position where it balances with the restoring force of the main spring 11.

Here, the displacement position of the pilot spool 20 is x, the displacement amount of the main spool 10 is X, the current flowing through the solenoid coil 32 is i, and the pressure of the C boat is
Assuming Pc, the following relationship holds: X=k ₁ x≒k ₂ Pc≒k ₃ i. However, k ₁ , k ₂ , and k ₃ are constants.

That is, since the main spool 10 is displaced in proportion to the current flowing through the solenoid coil 32, the flow rate of the fluid flowing through the main valve portion 1 changes depending on the value of the current flowing through the solenoid coil 32.

In addition, when controlling this proportional solenoid valve manually, by moving the movable element 35 to the right via the push rod 5 into which the adjusting screw 4 is screwed, it can be operated in the same manner as when driven by a solenoid. .

Furthermore, when this proportional solenoid valve is used as a normal on/off valve, when the solenoid is driven, a voltage sufficient to displace the pilot spool 20 to the rightward limit is supplied to the solenoid coil 32, and when the solenoid is operated manually, the push rod 5 is is driven to the right row limit.

The hydraulic circuit diagram of this proportional solenoid valve is shown in Figure 2, where 1', 2', and 3' indicate the main valve, pilot valve components, and solenoid on the right side, which are not shown in Figure 1. It is a constituent part.

Such a conventional proportional solenoid valve has a structure in which the pilot valve component 2 is externally attached to the solenoid component 3, and in terms of the system circuit, both the main valve component 1 and the pilot valve component 2 are open circuits. It is not a feedback type circuit.

[Problem that the invention attempts to solve]

However, this structure in which the pilot valve component is externally attached to the solenoid component requires a dedicated space for the pilot valve component, which limits miniaturization. It is difficult to make them compatible.

Furthermore, since the pilot valve component is of an open type, it is unsuitable for analog control.

Furthermore, since the pilot valve component does not have a pressure reducing function, leakage becomes large, and if the current flowing through the solenoid coil is constant, the pilot spool will not move at the position corresponding to that current. There were various problems such as the tendency to cause hydrolock.

In order to solve the problem of miniaturization, it is possible to house the pilot valve component inside the solenoid component, for example, in a fixed core, and such a solenoid valve for pneumatic circuits is already available. have also been proposed (for example, Japanese Patent Application Laid-Open No. 54-36623).

However, when trying to achieve this with a pilot proportional solenoid valve that requires high-pressure pilot oil pressure output, the fixed parts that form each port of the pilot valve component must be moved by the generated oil pressure, vibration, or impact force from a solenoid. Ensure that the pilot valve component and main valve component within the solenoid component are securely fixed within the fixed core to prevent oil from leaking outside in a narrow space. This was not possible because it was difficult to seal and connect directly.

This invention solves these problems by housing the pilot valve component of the proportional solenoid valve for hydraulic circuits within the fixed core of the solenoid component and directly connecting it to the main valve. It has achieved significant downsizing and power saving, always operates stably and reliably, prevents oil from leaking to the outside even when used at high oil pressure, and reduces pilot oil pressure. The purpose is to provide feedback and pressure reduction functions to make it suitable for analog control and also to solve the above-mentioned hydrolock problem.

[Means for solving problems]

Therefore, the proportional solenoid valve according to this invention is constructed as follows.

A pilot is pressed and driven by the movable element within the fixed iron core of the solenoid component, which has a fixed iron core fixedly installed in a core tube that has a solenoid coil on its exterior, and also has a magnetic movable element inside so that it can slightly slide. A pilot valve component consisting of a spool and a sleeve into which the pilot spool is slidably inserted and which forms three ports whose connection relationship can be switched by the sliding action is housed and provided, and a fixed iron core of the core tube is provided. A fitting part with the main valve part is provided at the fixed end, and the fixed core has a stepped hollow part with a large diameter hollow part on the fitting part side and a small diameter hollow part on the side facing the mover. The sleeve is fitted into the large diameter hollow part, and the pilot spool is brought into contact with the mover through the small diameter part, and the large diameter hollow part of the stationary core is partitioned by the end wall of the sleeve, and the open end of the sleeve is inserted into the large diameter hollow part. Connect the C port formed in the sleeve on the side to obtain the pilot hydraulic output, and connect the P port formed in the sleeve to be connected to the pump and the T port to be connected to the tank to each oil passage formed in the fixed iron core. , This sleeve is provided with an oil passage forming an orifice that guides the hydraulic pressure of the C port to the oil chamber formed between the pilot spool and the end wall of the sleeve, and a compression spring is installed between the pilot spool and the end wall of the sleeve. The solenoid component is directly connected to the main valve by attaching an O-ring to the outer periphery of the fitting part of the core tube and fitting it into the recess provided on the end face of the main body of the main valve part. Connect each of the oil passages formed in the main body to the oil passages of the P port and the T port formed in the main body, and make one end of the main spool of the main valve part face the open end side of the large diameter hollow part of the fixed iron core, A main spring is interposed between the end wall of the sleeve and the main body and main spool.

[Effect]

By using the above-mentioned means, this device houses the pilot valve component of a proportional solenoid valve for a hydraulic circuit within the fixed core of the solenoid component and connects it directly to the main valve, eliminating the need for a separate space for the pilot valve component. As a result, the proportional solenoid valve as a whole has been significantly downsized and saves power.

Furthermore, since the pilot valve component has a pressure reducing function and a feedback function for the pilot oil pressure output, stable analog control is possible.

Further, to explain the operation using FIGS. 3 and 4 corresponding to the embodiment, the solenoid component 3
The fitting portion 33a of the core tube 33 is fitted into the recess 13a provided on the end face of the main body 13 of the main valve portion 1 with an O-ring 38 attached to its outer periphery. Sealing is ensured, there is no risk of oil leakage, and there is no need to increase the diameter as in the case of sealing at the end face of the fixed core 34 forming the oil passages of each port.

Further, since one end of the main spool 10 of the main valve part 1 protrudes and faces into the open end recess 34a of the large diameter hollow part 34b of the fixed iron core 34 which communicates with the C port of the pilot valve component part 2, the main body 1
3, there is no need to form an oil passage for guiding the pilot oil pressure, and no extra space is required for this purpose.

Moreover, since the pilot oil pressure output from the pilot valve component 2 directly acts on the main spool 10, the main valve control operation is performed with a quick response.

Furthermore, the sleeve 23 of the pilot valve component
is the compression spring force f, the main spring 1
If the spring force of 2 is F, the solenoid
When OFF, the third
It is pressed to the left in the figure, and is pressed against the stepped portion in the hollow portion of the fixed iron core 34 and held fixed.

In this case, since the spring force of the main spring 12 is utilized, there is no need to provide a spring dedicated to pressing the sleeve.

When the solenoid is ON, the spool 23 is moved to the right by the movable element 35 to compress the compression spring 28, and the pilot hydraulic output is introduced into the oil chamber 25 through the oil passage 27, so that the sleeve 23 is connected to the main spring. The force that tries to move it to the right in the figure against the spring force of 12 increases, but
The pilot hydraulic output appears in the oil chamber formed on the outside of the end wall of the sleeve 23, and since the area of action on the outside of the end wall is naturally larger than the area on the inside, a force proportional to the difference between the hydraulic output and the area of action is generated. Therefore, the sleeve 23 is pressed to the left in FIG. 3, and even if the pilot oil pressure becomes high, the sleeve 23 is firmly fixed and held within the fixed iron core 34 (self-hold) without moving.

Therefore, reliable control operations can be performed at all times without causing any chatter phenomenon.

Furthermore, since there is no need to fix the sleeve 23 to the fixed core 34 by welding, gluing, etc., it is not necessary to disassemble or
Assembly and replacement of internal parts such as the pilot spool 24 are also easy.

〔Example〕

Hereinafter, embodiments of this invention will be described with reference to FIGS. 3 and 4 of the accompanying drawings. Note that portions corresponding to those in FIGS. 1 and 2 are given the same reference numerals, and explanations of those portions will be omitted.

First, the proportional solenoid valve shown in FIG. 3 has a pilot valve component 2 built into a solenoid component 3, and this solenoid component 3 is directly connected to the main valve component 1.

That is, the fixed core 34 of the solenoid component 3
A large diameter hollow part 34 having an open end recess 34a with the largest diameter formed on the side of the fitting part with the main valve part 1.
b and a small diameter hollow part 34c formed on the side facing the movable piece 35,
A non-magnetic sleeve 23 which is a fixed part is fitted into the large diameter hollow part 34b, and a movable element 35 which is slidably fitted into the sleeve 23 and has its left end penetrated through the small diameter hollow part 34c. A pilot valve component 2 consisting of a pilot spool 24 inscribed in the pilot valve component 2 is provided.

A pilot spool 24 is selectively connected to the sleeve 23 of the pilot valve component 2. Each oil passage forms three ports, namely the P port to be connected to the pump, the C port to obtain the pilot hydraulic output, and the T port to be connected to the tank, and the C port is connected to the end wall of the sleeve 23. an oil passage communicating with the open end side of the large diameter hollow part 34b of the fixed core 34 partitioned by the
Branching from the oil path, the pilot hydraulic pressure output (secondary hydraulic pressure) is sent to the pilot spool 24 and the sleeve 23.
An oil passage 27 forming an orifice leading to an oil chamber 25 formed between the end wall of Oil passages 34d and 34e communicating with the T port are formed.

The pilot spool 24 is given a leftward movement by a compression spring 28 interposed between the oil chamber 25 and the end wall of the sleeve 23.

Further, an oil passage 24a is formed in the pilot spool 24 so that the oil in the left and right oil chambers 37 and 25 can move as the pilot spool 24 moves.
A groove 35a through which oil flows is also provided in the direction of the outer circumferential axis of the pilot spool 24 and the movable element 35, thereby reducing resistance during movement of the pilot spool 24 and the movable element 35.

Then, the pilot valve component 2 is fixed to the fixed iron core 34.
After fitting the centering washer 11 to the main spool 10 and inserting the main spring 12 between the centering washer 11 and the sleeve 23, The fitting part 33a of the core tube 33 with the O-ring 38 attached to the outer periphery is connected to the main body 1 of the main valve part 1.
3, the flange plate 6 is fixed to the main body 13 with bolts 7, and the core tube 33 is fixed to the main body 13, thereby connecting to the main valve part 1.

Note that the core tube 33 of the solenoid component 3
A sealing O-ring 39 is interposed between the small diameter portion 33b and the housing 31.

Further, an O-ring 8 is interposed between the adjusting screw 4 and the small diameter portion 33b of the core tube 33, and a compression spring 9 is interposed between the push rod 5 and the movable element 35.

A pressure circuit diagram of the proportional solenoid valve constructed in this way is shown in FIG. In the figure, 1', 2', and 3' are the main valve section, pilot valve component, and solenoid component on the right side, which are not shown in FIG. 3.

Next, the operation of the embodiment configured as described above will be explained. In addition, components on the right side that are not shown in FIG. 3 are shown with dashes attached to the reference numerals.

First, when the solenoid coil 32 is not energized, the pilot spool 24 moves to the left due to the restoring force of the compression spring 28 and is in the state shown in FIG. The pilot hydraulic pressure is not applied to the main spool 10 of the main valve section 1, and it is pushed by the left and right main springs 12 and is in a neutral position, as shown in FIG. Both the A port and the B port of No. 1 are closed.

In this state, for example, when the left solenoid coil 32 is energized, the fixed core 34 and the movable element 35 attract each other, so that the movable element 35 moves to the right.

As a result, the pilot spool 24 is pressed by the mover 35 and moves to the right against the restoring force of the compression spring 28, so that the space between the C port and the T port is closed, the C port communicates with the P port, and the P port The pilot oil pressure is applied to the C port and pushes the main spool 10 to the right.

At this time, since the secondary oil pressure at port C is led to the oil chamber 25 via the oil passage 27, the oil pressure in the oil chamber 25 rises and a force in the leftward direction acts on the pilot spool 24 (feedback action).

Therefore, the pilot spool 24 stops at a position where the force in the rightward direction by the mover 35, the restoring force of the compression spring 28, and the feedback force in the leftward direction due to the hydraulic pressure in the oil chamber 25 are balanced.

Therefore, when the pilot oil pressure at the P port increases, it is transmitted to the oil chamber 25 via the C port and the oil passage 27, and the oil pressure inside the oil chamber 25 increases, causing the pilot spool 24 to move to the left and flow to the C port. Since the opening of the C port becomes narrower and throttle resistance is applied, the secondary hydraulic pressure of the C port is reduced.

From this state, when the pilot oil pressure of the P port decreases, the oil pressure in the oil chamber 25 decreases, the pilot spool 24 moves to the right, the opening to the C port widens, and the secondary oil pressure of the C port increases. Ru.

In this way, even if the primary oil pressure at the P port fluctuates, the secondary oil pressure at the C port is kept substantially constant.

In this case, the final displacement of the pilot spool 24 is x, the final displacement of the main spool 10 is x,
If the pressure at the C port is Pc, and the current flowing through the solenoid coil ₃₂ is i, _{then the} following relationship holds: However, k ₁ , k ₂ , and k ₃ are constants.

That is, since the main spool 10 is displaced approximately in proportion to the current flowing through the solenoid coil 32, the amount of oil flowing through the main valve portion 1 changes depending on the value of the current flowing through the solenoid coil 32.

According to this embodiment, the fitting portion 33a of the core tube 33 of the solenoid component 3 is provided with an O
The ring 38 is attached to the main body 1 of the main valve portion 1.
Since the oil passage 13 is fitted into the recess 13a formed on the end face of the fixed core 34, the O-ring 38 reliably seals the oil from the outside, eliminating the risk of oil leakage, and there is no need to increase the diameter as would be the case if the oil passage 13 is sealed on the end face of the fixed core 34 which forms the oil passage for each port.

Further, since one end of the main spool 10 of the main valve part 1 protrudes and faces into the open end recess 34a of the large diameter hollow part 34b of the fixed iron core 34 which communicates with the C port of the pilot valve component part 2, the main body 1
3, there is no need to form an oil passage for guiding the pilot oil pressure, and therefore no extra space is required.

Moreover, since the pilot oil pressure output from the pilot valve component 2 directly acts on the main spool 10, the main valve control operation is performed with a quick response.

Furthermore, the sleeve 23 of the pilot valve component
is the compression spring force f, the main spring 1
If the spring force of 2 is F, the solenoid
When OFF, the third
It is pressed to the left in the figure, and is pressed against the step in the hollow part of the fixed iron core 34 and held fixed.

In this case, since the spring force of the main spring 12 is utilized, there is no need to provide a spring dedicated to pressing the sleeve.

When the solenoid is ON, the spool 23 moves to the right by the movable element 35 to compress the compression spring 28, and pilot hydraulic output is introduced into the oil chamber 25 through the oil passage 27, so that the sleeve 23 is connected to the main spring. The force that tries to move it to the right in the figure against the spring force of 12 increases, but
The pilot hydraulic output appears in the oil chamber formed on the outside of the end wall of the sleeve 23, and since the area of action on the outside of this end wall is naturally larger than that on the inside, a force proportional to the difference between the hydraulic output and the area of action occurs. Therefore, the sleeve 23 is pushed to the left in FIG. 3, and even if the pilot oil pressure becomes high, the sleeve 23 does not move and is held fixed (self-hold) within the fixed iron core 34.

Therefore, reliable control operations can be performed at all times without causing any chatter phenomenon.

Furthermore, since there is no need to fix the sleeve 23 to the fixed core 34 by welding, gluing, etc., it is not necessary to disassemble or
Assembly and replacement of internal parts such as the pilot spool 24 are also easy.

In addition, when this proportional solenoid valve is driven manually, by screwing in the adjusting screw 4 and moving the mover 35 to the right via the push rod 5 and spring 9, it is operated in the same manner as when driven by a solenoid. be able to. Note that this adjustment screw 4 is used for zero adjustment (positioning) of the pilot spool 24.
It is also used for purposes.

In addition, when using this proportional solenoid valve as an on/off valve, when the solenoid is driven, a voltage sufficient to displace the pilot spool 24 to the rightward limit is supplied to the solenoid coil 32, and when it is manually driven, the voltage is supplied to the solenoid coil 32 by the push rod 5. It is sufficient to push the movable element 35 to the right limit.

[Effect of idea]

In this way, the proportional solenoid valve according to this invention has a pressure reducing function in the pilot valve, and the pilot valve components are made into a feedback type in terms of the system circuit.
Moreover, the pilot valve component is housed within the fixed core of the solenoid component.

Therefore, there is no need for a dedicated space for the pilot valve component, resulting in a smaller size, and the solenoid component and pilot valve component can share pilot parts of different sizes and be converted into a cartridge. be.

In addition, the pilot spool is constantly moving and self-cleaning due to the decompression effect.
No sticking occurs, and since the pilot oil pressure is reduced, there is less leakage.

Furthermore, since there is a feedback effect, there is no possibility that the pilot spool will suddenly displace and cause a shock.

Further, since the seal between the pilot valve component and the main valve part can be reliably achieved in a small space, there is no risk of oil leakage even when used in a high-pressure hydraulic circuit.

In addition, the sleeve of the pilot valve component is fixed and held only by spring force when the solenoid is OFF, making it easy to disassemble, assemble, and replace internal parts.When the solenoid is ON, it is self-holding by the pilot hydraulic output. Therefore, even if the pilot oil pressure increases or vibrations or shocks are applied, the positional relationship between the pilot spool and the sleeve will not shift, so there will be no chattering phenomenon.
Reliable control operations can be performed at all times.

Therefore, the proportional solenoid valve according to this invention can be used in various applications such as electromagnetic flow control valves, electromagnetic flow/directional switching valves, and intrinsically safe control valves, and can be miniaturized and made into a cartridge. It is suitable for control, reduces leakage, and has the effect of being less likely to cause hydrolock.

[Brief explanation of drawings]

Figure 1 is a vertical sectional view showing the left half of an example of a conventional proportional solenoid valve, Figure 2 is a hydraulic circuit diagram of the entire hydraulic circuit, and Figure 3 is the left side of a proportional solenoid valve that is an example of this invention. FIG. 4 is a longitudinal cross-sectional view showing a half portion, and a hydraulic circuit diagram of the entirety thereof. 1... Main valve part, 2... Pilot valve component part, 3
... Solenoid component, 10 ... Main spool, 12 ... Main spring, 13 ... Main body, 23 ... Sleeve, 24 ... Pilot spool, 32 ... Solenoid coil, 33 ...
Core tube, 34... fixed iron core, 35... mover.

Claims (1)

[Claims for Utility Model Registration] A pilot valve driven by a solenoid including a solenoid coil, a fixed core, and a movable element, and a main valve driven by pilot hydraulic pressure guided through the pilot valve. In the proportional solenoid valve that controls the amount of oil flowing through the main valve according to the current value flowing through the solenoid, a fixed iron core is fixed in a core tube that is covered with a solenoid coil, and a magnetic mover is slightly attached. A pilot spool pressed and driven by the movable element and the pilot spool are slidably fitted into a fixed core of a solenoid component that is slidably installed, and the connection relationship is established by sliding. A pilot valve component consisting of a sleeve forming three ports to be switched is housed and provided, and a fitting part with the main valve part is provided at the end of the core tube to which the fixed iron core is fixed, A stepped hollow part is formed in which the fitting part side is a large-diameter hollow part and the side facing the movable part is a small-diameter hollow part, and the sleeve is fitted into the large-diameter hollow part, and the small-diameter part The pilot spool is brought into contact with the mover through the sleeve, and the large diameter hollow part of the fixed core is partitioned by the end wall of the sleeve, and the open end thereof is communicated with a C port formed in the sleeve for obtaining a pilot hydraulic pressure output. , a P port formed in the sleeve to be connected to a pump and a T port to be connected to a tank are connected to each oil passage formed in the fixed iron core, and the hydraulic pressure of the C port is connected to the pilot spool in the sleeve. An oil passage forming an orifice leading to an oil chamber formed between the sleeve and the end wall of the sleeve is provided,
A compression spring is interposed between the pilot spool and the end wall of the sleeve, and an O-ring is attached to the outer periphery of the fitting portion of the core tube, and the fitting portion of the core tube is fitted into a recess provided on the end surface of the main body of the main valve portion. The solenoid component is directly connected to the main valve part, each oil passage formed in the fixed iron core is connected to the P port and T port oil passages formed in the main body, and the main valve part is connected directly to the main valve part. A proportional electromagnetic device characterized in that one end of the spool faces the open end side of the large-diameter hollow portion of the fixed core, and a main spring is interposed between the end wall of the sleeve, the main body, and the main spool. valve.