JP2524009Y2 - Proportional solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a structure of a proportional solenoid valve used for a fluid control device.

[Conventional technology]

FIG. 5 is a sectional view showing a structure of a spool valve used in a conventional proportional solenoid valve, wherein 1 is a sleeve, 2 is a sleeve 1
3 is a fluid input passage, 4 is an input port provided at the end of the fluid input passage, 5 is a fluid discharge passage,
6 is a discharge port and 7 is a spring.

Next, the operation will be described. The spool 2 has an opening / closing land portion 2a for opening and closing the discharge port 6 and a non-opening / closing land portion 2b having the same diameter provided opposite to the opening / closing land portion 2a, and the spool 2 slides inside the sleeve 1. Thus, the opening and closing of the discharge port 6 is performed by the opening and closing land 2a. That is, a fluid of a predetermined pressure always flows from the input port 4 through the fluid input passage 3 to the space between the opening / closing land portion 2a and the non-opening / closing land portion 2b. It is adjusted according to the degree of.

[Problems to be solved by the invention]

Since the spool valve structure of the conventional proportional solenoid valve is configured as described above, the fluid flows from the wide passage to the discharge port 6 which is a narrow passage, the flow velocity increases at that portion, and the pressure applied to the opening / closing land 2a is increased. Decrease. Therefore, even if the diameter of the opening / closing land portion 2a and the diameter of the non-opening / closing land portion 2b are the same, the balance of the axial force of the spool 2 is lost, and the fluid force for moving the spool 2 to the left in FIG. There has been a problem that it occurs in proportion to the square of the flow rate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a proportional solenoid valve capable of maintaining the balance of the axial force of the spool.

[Means for solving the problem]

The proportional solenoid valve according to the present invention connects the discharge port to a flow compensation chamber provided outside the non-opening / closing land, and when the discharge port is opened, the fluid in the flow compensation chamber connects the non-opening / closing land to the opening / closing land. A throttle is provided in the fluid discharge passage of the flow rate correction chamber to generate a pushing force in the direction.

[Action]

The proportional solenoid valve according to the present invention provides a force that presses the non-opening / closing land portion of the spool toward the opening / closing land portion by providing a throttle in the flow rate correction chamber and the fluid discharge passage, and when the discharge port is opened. The resulting imbalance in the axial force of the spool is counteracted and the axial force balance is maintained.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

1 and 2 are sectional views showing the structure of a proportional solenoid valve according to this embodiment. FIG. 1 shows a state in which the discharge port is closed, and FIG. 2 shows a state in which the discharge port is open. Represents. FIG. 3 shows the performance of the fluid supply means, showing the relationship between the flow rate and the pressure of the fluid, and FIG. 4 shows the relationship between the current value of the solenoid valve pressing means and the pressure of the fluid output passage.

In the drawing, 1 is a sleeve, 2 is a spool having an opening / closing land portion 2a and a non-opening / closing land portion 2b of the same diameter sliding in the sleeve 1, and a pressure adjusting land portion 2c smaller in diameter than both the land portions, and 3 is a fluid. The input passage 4 is an input port provided at the end of the fluid input passage, 5 is a fluid discharge passage, 6 is a discharge port, 8 is a fluid output passage for guiding a fluid controlled to a predetermined pressure, and 9 is an output port. Numeral 10 is an electromagnetic pressing means for moving the spool 2 in the axial direction, 10a is a rod, and 10b is a spring. Reference numeral 11 denotes a flow rate correction chamber provided on the rear side of the non-opening / closing land portion 2b and connected to the fluid discharge passage 5. A throttle for generating a pushing force (rightward in the figure), 13 is a fluid supply means (for example, a hydraulic pump) for supplying fluid to the fluid input passage 3, and 14 is a fluid of a predetermined pressure sent from the fluid output passage 8. Control means to be controlled, 15 is a pressure adjustment chamber, and 16 is a pressure adjustment passage.

Next, the operation will be described. The flow rate and pressure of the fluid supplied from the fluid supply means 13 to the fluid input passage 3 are determined by the capacity of the liquid supply means 13. Here, FIG. 3 shows the performance of the hydraulic pump when the hydraulic pump is used as the fluid supply means 13, in which the vertical axis shows the flow rate (1 / min) and the horizontal axis shows the pressure (kgf / cm ² ). , The solid line 1 represents the maximum capacity of the pump. Fluid supply means of the hydraulic pump
The capacity actually used as 13 is not the solid line 1 which is the maximum capacity of the pump, but an area having a width indicated by a shaded portion. This is because one hydraulic pump is used not only for one control means 14 but for a plurality of other control means, so that the flow rate and the pressure are reduced below the maximum capacity of the pump. As described above, since the flow rate and the pressure change with the above-mentioned width depending on the use state of the hydraulic pump, in the conventional spool valve structure (FIG. 5), the fluid force acting on the opening / closing land portion 2a when the discharge port is opened greatly changes. The purpose of the present invention is to minimize the effect of this change in fluid force.

The fluid passing through the fluid input passage 3 is transferred to the sleeve 1
Pressure chamber 15 sandwiched between an opening / closing land portion 2a and a non-opening / closing land portion 2b from an input port 4 provided facing an inner peripheral surface 1a of the air conditioner.
When the opening / closing land portion 2a closes the discharge port 6 as shown in FIG. Output from port 9. Then, the fluid flowing out of the output port 9 passes through the fluid output passage 8 and controls the control means 14.

In addition, a part of the fluid passing through the fluid input passage 3 passes through the pressure adjustment passage 16 and applies pressure to the pressure adjustment land 2c provided outside the non-open / close land 2b to push the spool 2 rightward in the drawing. I have. The force of the fluid is balanced by the rod 10a of the electromagnetic pressing means 10 pressing the opening / closing land 2a.

Next, the control means 14 is set to a predetermined pressure value (fluid supply means).
When the control is to be performed with a value lower than the pressure of the fluid flowing out of the fluid 13, first, the electromagnetic value of the electromagnetic pressing means 10 is set to a value corresponding to the predetermined pressure value. As a result, the spring 10
Contrary to the urging force of b, an electromagnetic force is generated in the rod 10a in the right direction in the drawing according to the current value, and the electromagnetic pressing means 10 generates a difference between the urging force of the spring 10b and the electromagnetic force (the urging force is A force that pushes the opening / closing land portion 2a leftward in the drawing by a magnitude larger than the electromagnetic force is generated. On the other hand, fluid supply means (hydraulic pump)
The pressure of the fluid sent from the passage 13 and passing through the pressure adjustment passage 16 pushes the pressure adjustment land 2c rightward in the drawing. At a position where this force and the force of the electromagnetic pressing means 10 are balanced, the spool 2 stops. The reason why the area of the adjustment land portion 2c is set smaller than the area of the other land portions 2a and 2b is that the pressing force of the spool 2 due to the pressure of the liquid is set to be small, so that the electromagnetic pressing means that balances this force. This is because the pressing force of 10 can also be set small, thereby reducing the size of the electromagnetic means 10.

FIG. 2 is a diagram in the case where the pressure of the fluid supply means (hydraulic pump) 13 is too high, and shows the difference between the force pressing the adjustment land 2c rightward in the drawing and the leftward force controlled by the electromagnetic pressing means 10. By adjustment, the discharge port 6 is opened by a predetermined opening. That is, the pressure of the fluid sent to the control means 14 is adjusted by discharging a fixed amount of the fluid in the pressure adjustment chamber 15 from the discharge port 6. However, in a state where the discharge port 6 is open, the pressure decreases in the vicinity of the discharge port in proportion to the square of the flow rate.
The force balance between the open / close land portions 2a and the non-open / close land portions 2b having the same diameter is broken, and the spool 2 tends to move leftward in the drawing. In the present embodiment, the fluid discharged from the discharge port 6 is sent to the flow correction chamber 11 through the fluid discharge passage 5,
A throttle 12 generates a correction pressure in the fluid in the flow correction chamber 11. Then, the spool 2 is moved to the right side in the drawing by this correction pressure, and the imbalance in force due to the decrease in pressure near the discharge port is corrected. As described above, as the flow rate of the fluid discharged from the discharge port 12 increases, the pressure near the discharge port decreases and the fluid force for moving the spool 2 to the left in the drawing increases, but the fluid flows through the fluid discharge passage 5. Since the flow rate is also increased and the correction pressure in the flow rate correction chamber 11 by the throttle 12 is increased, it is possible to perform correction in accordance with fluctuations in the flow rate and pressure of the fluid supply means 13.

FIG. 4 is an example showing the relationship between the current value of the electromagnetic pressing means 10 and the pressure of the fluid output passage 8 in this embodiment, and the pressure is proportional to the current value. That is, by setting the current value of the electromagnetic pressing means 10, the fluid supply means 13
Regardless of the pressure and flow rate, a fluid at a desired pressure can always be sent to the control means 14.

As described above, according to the present embodiment, it is possible to always send a fluid having a stable pressure to the control means 14 without disturbing the balance of the axial force of the spool 2 due to the fluid force generated by opening and closing the discharge port 6. it can. Also, discharge port 6
Since the pressure is corrected by the fluid discharged from the pump, the optimum correction can be performed according to the fluctuation of the pressure and the flow rate of the fluid supply means (hydraulic pump) 13.

[Effect of the invention]

As described above, according to the present invention, the discharge port is connected to the flow rate correction chamber provided outside the non-opening / closing land portion, and the pressure is generated in the fluid in the flow rate correction chamber by the throttle. Can be maintained, and a fluid having a stable pressure can always be sent to the control means. Further, since the pressure is corrected by the fluid discharged from the discharge port, the correction can be performed according to the fluctuation of the pressure and the flow rate of the fluid supply means.

[Brief description of the drawings]

1 and 2 are sectional views showing the structure of a proportional solenoid valve according to an embodiment of the present invention. FIG. 1 shows a state in which the discharge port is closed, and FIG. 2 shows a state in which the discharge port is open. Each state is shown. FIG. 3 is a view showing an example of the performance of the fluid supply means of the present invention, FIG. 4 is a view showing an example of the relationship between the current value of the electromagnetic pressing means and the pressure of the fluid output passage of the present invention, FIG.
FIG. 1 is a sectional view showing a spool valve structure used for a conventional proportional solenoid valve. In the drawing, 1 is a sleeve, 2 is a spool, 2a is an opening / closing land portion, 2b is a non-opening / closing land portion, 3 is a fluid input passage, 4 is an input port, 5 is a fluid discharge passage, 6 is a discharge port, and 8 is a fluid output. A passage, 9 is an output port, 10 is an electromagnetic pressing means, 11 is a flow rate correction chamber, 12 is a throttle, 13 is a fluid supply means, 14 is a control means, 15 is a pressure adjustment chamber, and 16 is a pressure adjustment passage. In the drawings, the same reference numerals indicate the same or corresponding parts.

Continuation of the front page (56) References JP-A-59-9381 (JP, A) JP-A-63-186977 (JP, U) JP-A-2-34803 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A spool slidably disposed in a sleeve and having at least an opposing open / close land and a non-open / close land, and a pressurized fluid supplied from a fluid supply means. A fluid input passage that guides the pressure fluid in the pressure regulation chamber to an external control unit, and a fluid output passage that guides the pressure fluid in the pressure regulation chamber to an open / close land portion of the spool. By doing
A proportional solenoid valve comprising: a pressing means for moving the spool in the axial direction; and a discharge port provided to face an inner peripheral surface of the sleeve so as to be opened and closed by the opening and closing land. Connected to the flow rate correction chamber provided outside the non-opening / closing land, and in a state where the discharge port is open,
A proportional solenoid valve, wherein a throttle is provided in a fluid discharge passage downstream of the flow rate correction chamber so as to generate a force for pushing the non-opening / closing land portion toward the opening / closing land portion in the fluid in the flow rate correction chamber.