JPS6315932Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic proportional flow control device that controls a flow rate by increasing or decreasing a current value to a DC electromagnetic device.

In an electromagnetic proportional flow control device such as that disclosed in Japanese Patent Publication No. 54-30128 previously filed, a pressure-receiving surface of the same area provided opposite to a movable valve member forming a constriction part is provided with a constriction that is constantly compensated by a pressure compensation valve. Applying pressure before and after the constriction part to the movable valve member against the pressing force caused by the pressure difference before and after the constriction part, it is possible to change the acting force at each position of the movable iron core approximately equally in response to changes in the current value. , the movable valve member is positioned by applying the acting force of a DC electromagnetic device having a characteristic that the acting force decreases as the movable iron core is displaced in the direction of the acting force, and the pressing force and the acting force are balanced. The flow rate is controlled according to the current value. However, it is not easy to manufacture a DC electromagnetic device with such acting force characteristics, and when pressure fluid suddenly flows into the valve, the opening area of the throttle section increases rapidly, causing a jumping phenomenon. However, if the movable valve member is made to slide slowly in order to suppress this, there are drawbacks such as poor response when the current value to the DC electromagnetic device is increased or decreased.

The present invention facilitates the fabrication of DC electromagnetic devices,
Furthermore, the present invention provides an electromagnetic proportional flow rate control device that satisfactorily prevents the phenomenon of jumping at the beginning of flow and has excellent operability.

For this reason, in the present invention, the movable valve member that forms the throttle part with the throttle opening of the sliding hole is directed to increase the opening area of the throttle part against the pressing force caused by the pressure difference before and after the throttle part. The action of a DC electromagnetic device that can change the acting force at each position of the movable core equally in response to changes in the spring force and current value of the spring, and has the characteristic that the acting force remains approximately constant even if the movable core is displaced. The movable valve member is movably installed at the end of the movable valve member, and the spring force applied to one end pushes and slides the movable valve member in the direction of closing the throttle part, and the pressure is released by the pressure fluid upstream of the throttle part. A moving member is provided to control the flow rate according to the current value to the DC electromagnetic device.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

In Fig. 1, reference numeral 1 denotes the main body of the electromagnetic proportional flow control device, which is provided with a flow path 4 that communicates an inflow port 2 and an outflow port 3. A movable valve 6 is installed.

The pressure compensation valve 5 consists of a pressure compensation valve member 7 and a spring 8, and compensates for a constant pressure difference before and after the constriction part of the movable valve 6. It has a passage 10 for introducing downstream pressure.

The movable valve 6 has a cylindrical hole 1 provided intersecting the flow path 4.
1, a movable valve member 14 slidably inserted into a sliding hole 13 formed in the fixed sleeve, a closing member 15 provided at the opening of the sliding hole, and a movable valve member. It consists of a spring 16 that is engaged between a closing member 14 and a closing member 15. The movable valve member 14 has large diameter portions 19 and 20 provided with opposing pressure receiving surfaces 17 and 18 of the same area, and the fixed sleeve 1
Pressure chambers 21, 22, and 23 are formed within 2.
24 is a throttle opening provided in the sliding hole 13 of the fixed sleeve 12 in communication with the flow path 4, and forms a throttle part 25 whose opening area changes with the large diameter part 20 of the movable valve member 14. There is. The spring 16 is provided within the pressure chamber 21 and applies a spring force to the movable valve member 14 in the direction of increasing the opening area of the throttle portion 25.
The pressure chamber 23 is communicated with the flow path 4 via the passage 26 so that the pressure upstream of the constriction portion 25 acts on the pressure chamber 23.
1 is configured such that pressure downstream of the constriction portion 25 acts through the passage 27. 28 is the movable valve member 14
A drain flow path is formed inside to drain leaked fluid to the low pressure side. 29 and 30 are movable valve members 1
The small diameter portions 30 are formed at both ends of the electromagnetic proportional flow control device body 1 and are provided to penetrate through the end wall of the fixed sleeve 12 and the closing member 15. Electromagnetic device 31
The acting force of Furthermore, the tip of a movable piston 33 as a movable member disposed coaxially with the movable valve member 14 and biased by a spring 32 is pressed into engagement with the other end of the small diameter portion 29 . 34 is a pressure chamber formed on one end side of the movable piston 33, which communicates with the flow path 4 on the inlet port 2 side of the pressure compensating valve 5 via a passage 35;
The spring chamber 36 in which the movable valve member 14 is installed communicates with the drain passage 28 of the movable valve member 14 and communicates with the low pressure side via a passage 37. The spring force of the spring 32 is set to be stronger than the spring force of the spring 16 of the movable valve 6, and when pressure is not flowing into the flow path 4, the movable valve member 14 is pressed and slid to the left sliding end in the figure to throttle it. Part 2
5 is now closed.

The DC electromagnetic device 31 consists of a fixed iron core 38, a movable iron core 39, and a coil 40. By applying DC current to the coil, the movable iron core is attracted to the fixed iron core. The operating force of the movable valve member 14 is applied through the movable valve member 14. and DC electromagnetic device 31
The acting force characteristics are such that by increasing or decreasing the value of the DC current flowing through the coil 40, the acting force at each position of the movable core can be changed approximately equally, and the acting force is approximately constant even if the movable core is displaced. It is designed to be applied in the direction of force.

Next, the operation of the above configuration will be explained.

From the illustrated state in which there is no pressure fluid flowing into the inlet 2 and the movable valve member 14 is pressed and slid to the left sliding end by the spring force of the spring 32 via the movable piston 33, no pressure is applied to the inlet 2. When the fluid flows in, the pressure fluid passes through the flow path 4 and the pressure compensating valve 5 and flows into the pressure chamber 22 of the movable valve 6, but does not flow out to the outlet 3 because the throttle part 25 is closed. In addition, the pressure fluid flows into the pressure chamber 34 through the passage 35, bends the spring 32, and moves the movable piston 33 to the right, and the movable piston 33 releases the pressure from the movable valve member 14, causing the force of the spring 32 to move. Upon release of its action on the valve member 14, the pressure fluid flows into the pressure chamber 23 through the passage 26 to press and hold the movable valve member 14 in the position shown.

Next, when the coil 40 of the DC electromagnetic device 31 is energized, the movable valve member 14 slides to the right in the figure due to the force of the spring 16 resisting the pressing force acting in the pressure chamber 23 and the acting force of the DC electromagnetic device, and the constriction portion 25 The pressurized fluid flows out to the outlet 3 by forming an opening. At this time, the throttle part 25 gradually increases its opening area from the closed state and the pressure fluid flows out to the outlet 3, so that an excessive flow rate is prevented from suddenly passing through the throttle part at the beginning of the flow, thereby preventing the occurrence of the jumping phenomenon. can. When a flow of pressure fluid occurs in the flow path 4, the movable member 14 is constantly compensated by the pressure compensating valve 5, and has a constant pressing force based on the pressure chambers before and after the constriction part 25, the force of the spring 16, and the direct current electromagnetic device. It is positioned at an equilibrium position with the acting force of 31. FIG _. 2 shows the relationship between the force acting on the movable valve member ₁₄ and the displacement of the movable valve member. The force F _M is the acting force of the DC electromagnetic device 31 and the movable valve member 14
is the equilibrium position of the pressing force F _C , the spring force F _S , and the acting force F _M of the DC electromagnetic device, that is, the acting force F acting in the left direction, which is obtained by subtracting the spring force F _S from the pressing force F _C , and the acting force F acting in the right direction The opening area of the diaphragm 25 is set at a position X that is in equilibrium with the acting force F _M of the DC electromagnetic device. The flow rate of the pressure fluid passing through the constriction part 25 and flowing out to the outlet 3 is constant regardless of pressure fluctuations at the inlet 2 and the outlet 3 because the pressure difference before and after the constriction part 25 is compensated for by the pressure compensating valve 5. It is controlled at a constant level. Coil 4 of DC electromagnetic device 31
When the current value applied to 0 is increased, the acting force F _M increases as shown in F ₁ in the figure, and the movable iron core 39 is displaced toward the fixed iron core 38 side in the direction of the acting force, and the movable valve member 1
4 is the acting force F and the acting force F ₁ of the DC electromagnetic device.
The flow rate is increased by being positioned at the position X ₁ shown in the _figure , where the balance is balanced, and _the current value is decreased. By increasing or decreasing the value, the position of the movable valve member 14 can be changed to arbitrarily set the flow rate. In addition, the moving piston 33
Once the pressure fluid flows into the flow path 4, the spring 3
2 is deflected and positioned at the right moving end in Figure 1,
The force of the spring 32 does not contribute any force to the movable valve member 14.

In this way, the present invention provides a movable valve member that forms a throttle part with the throttle opening of the sliding hole, in the direction of increasing the opening area of the throttle part against the pressing force caused by the pressure difference before and after the throttle part. The acting force of a DC electromagnetic device that has the characteristic that the acting force at each position of the movable core can be changed approximately equally in response to changes in the spring, spring force, and current value, and that the acting force remains approximately constant even if the movable core is displaced. By providing this, it is easy to manufacture the DC electromagnetic device, and the movable valve member is movably installed at the end of the movable valve member, and the movable valve member is pressed in the direction of closing the throttle part by the spring force applied to one end. Since the moving member is provided so that the pressure is released by the pressure fluid upstream of the sliding constriction portion, the jumping phenomenon at the beginning of flow can be effectively prevented without degrading the response performance of the movable valve member.

Further, by increasing the current value of the DC electromagnetic device, the control flow rate increases and operability is improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an electromagnetic proportional flow rate control device showing an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between force acting on the movable valve member 14 and displacement. 4...Flow path, 5...Pressure compensation valve, 14...Movable valve member, 16...Spring, 17, 18...Pressure receiving surface,
24... Aperture aperture, 25... Aperture section, 26, 27
... passage, 31 ... DC electromagnetic device, 32 ... spring, 33 ... moving member, 39 ... movable iron core.

Claims (1)

[Scope of utility model registration request] A movable valve member that is slidably inserted into a sliding hole and has a throttle opening in the sliding hole to form a throttle part in the flow path and has opposing pressure receiving surfaces of the same area, and a pressure difference before and after the throttle part. a pressure compensating valve that compensates for a constant value; a passage means that allows the pressures before and after the throttle to act on the pressure receiving surface; and A spring applies a spring force to the movable valve member in the direction of increasing the opening area of the throttle part, and the acting force at each position of the movable core can be changed approximately equally in response to changes in the current value, and the movable core can be displaced. a direct current electromagnetic device that has a characteristic of making the acting force substantially constant and applies an acting force to the movable valve member in a direction that resists the pressing force, and a DC electromagnetic device that is movably installed at an end of the movable valve member and applies it to one end the movable valve member is provided so as to press and slide the movable valve member in the direction of closing the throttle part by a spring force, and release the pressure by the pressure fluid upstream of the throttle part, and the action of the pressing force, the spring force, and the DC electromagnetic device is provided. An electromagnetic proportional flow control device that positions the movable valve member in balance with the force and controls the flow rate.