JPH08200540A - Solenoid valve - Google Patents

Abstract

PURPOSE: To enable a flow rate equivalent to that at high temperatures to be secured at low temperatures without using a temperature sensor, correcting duty ratio, or deteriorating responsivenss and pulsation at high temperatures. CONSTITUTION: A first and a second plungers 42, 44 are arranged in series inside a coil 20 to which a constant voltage is applied, and are energized toward the valve closing side (leftward in the figure) respectively by first and second compression coil springs 46, 48, and at high temperatures at which the coil 20 has large electrical resistance and a small electromagnetic force the first plunger 42 is moved to a first valve opening position where it abuts to the second plunger 44. At low temperatures at which the coil 20 has small electrical resistance and a large electromagnetic force, the first plunger 42 is moved to a second valve opening position where it abuts to a core 16 via the second plunger 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic on-off valve, and more particularly to an electromagnetic on-off valve that can secure a flow rate at a low temperature where fluidity of a fluid is lowered and at the same time as a high temperature.

[0002]

2. Description of the Related Art An electromagnetic on-off valve that opens a flow path by moving a valve element such as a poppet or a spool to a valve opening side via a plunger (movable iron core) by applying a constant voltage to a coil for excitation. However, it is used in various fields such as a hydraulic circuit of an automatic transmission for a vehicle. Such an electromagnetic on-off valve
Although the flow path is opened and closed depending on whether or not a voltage is applied, the flow rate per unit time can be continuously changed by controlling the duty of the voltage application time.

By the way, since the valve opening degree of such an electromagnetic on-off valve, that is, the flow cross-sectional area of the fluid when the flow path is opened is constant, the fluid temperature is low and the fluidity is poor (high viscosity).
There is a difference in the flow rate per unit time between the case where the temperature is high and the fluidity is good (the viscosity is low), and there is an inconvenience that the flow rate is low at low temperature as compared with high temperature and the response is poor. . Such inconvenience is remarkable in the case of a liquid such as oil or a gel-like fluid whose viscosity largely changes depending on the temperature. In the solenoid valve for the hydraulic circuit of the automatic transmission for a vehicle, if the response is poor, the engagement of the shift clutch or the brake is delayed and a shift shock or the like occurs. Therefore, for example, as described in Japanese Patent Application Laid-Open No. 2-86422, the temperature of the fluid is measured by a temperature sensor, and the duty ratio of the duty control is corrected according to the temperature to change the temperature. Regardless of the above, it is possible to obtain an appropriate flow rate.

[0004]

However, in that case, since the temperature sensor is required and the correction value for correcting the duty ratio according to the fluid temperature needs to be stored in the data map or the like, the device configuration is required. The control became complicated, and I was not always fully satisfied. In addition, the valve opening of the valve itself is enlarged so that a sufficient flow rate can be obtained even at low temperature, and the duty control limits the flow rate to a predetermined flow rate. As a result, the opening / closing time becomes long, the responsiveness at high temperature deteriorates, and the pulsation of the flow rate and pressure accompanying the duty control increases. In the hydraulic circuit of the automatic transmission, it is necessary to avoid impairing the responsiveness and pulsation at high temperature because the engine is initially started at a low temperature and the normal running after warm-up is a high temperature.

Since the Japanese Patent Laid-Open No. 2-86422 uses a proportional solenoid valve for continuously controlling the valve opening itself, there is no pulsation such as duty control.
It is possible to secure a sufficient flow rate at low temperature without impairing the responsiveness at high temperature, but the valve itself is complicated and expensive.

The present invention has been made in view of the above circumstances. An object of the present invention is to impair responsiveness and pulsation at high temperature without using a temperature sensor or correcting a duty ratio. The purpose of the present invention is to provide an electromagnetic on-off valve that can secure the same flow rate as that at high temperature even at low temperature.

[0007]

In order to achieve the above object, the first aspect of the present invention applies a constant voltage to a coil to excite the coil so that the valve body is opened toward the valve opening side via a plunger. In the electromagnetic on-off valve which is moved to open the flow path, the plunger of the plunger is resisted against the urging force of the urging means for urging the plunger toward the valve closing side based on the increase of the electromagnetic force accompanying the temperature decrease of the coil. It is characterized in that the amount of movement to the valve opening side is increased so that the valve opening becomes larger at low temperature than at high temperature.

[0008]

In other words, since the coil used for the solenoid opening / closing valve is made of metal such as copper enameled wire, the electric resistance becomes smaller as the temperature becomes lower, and when a constant voltage is applied. Therefore, the current value increases and the electromagnetic force increases. Then, by utilizing the increase of the electromagnetic force, the amount of movement of the plunger toward the valve opening side is increased against the biasing force of the biasing means for biasing the plunger toward the valve closing side. At times, the valve opening was made larger than at high temperature, so that even if the temperature is low and the fluidity is poor (high viscosity),
It is possible to secure the same flow rate as when the temperature is high and the fluidity is good (the viscosity is low). Further, since the amount of movement of the plunger is small at high temperatures, it is possible to maintain the pulsation of the flow rate and pressure associated with the responsiveness and duty control to the same level as in the conventional case.
Furthermore, in order to increase the valve opening by utilizing the increase in electromagnetic force due to the decrease in temperature, a temperature sensor is used to measure the temperature of the fluid, and a correction value for correcting the duty ratio according to the fluid temperature is used as a data map. No special means or control for changing the valve opening degree according to the temperature, such as memorizing at, is required, and the entire apparatus including the control system for opening and closing the valve can be configured easily and inexpensively.

The above is the operation and effect peculiar to the first invention, but the relationship between the temperature and the valve opening degree increases stepwise even if the valve opening degree continuously increases as the temperature decreases. However, it is desirable to set it based on the relationship between the fluidity of the fluid and the temperature. For example, when the fluidity of the fluid suddenly drops at a predetermined temperature, the valve opening may be increased suddenly near the predetermined temperature.

Further, since the electromagnetic force of the coil continuously increases as the temperature decreases, by appropriately setting the urging force of the urging means, the urging force of the urging means and the electromagnetic force (strictly speaking, to the plunger). The amount of movement of the plunger, that is, the valve opening, can be continuously changed by the balance with the suction force). For example, the urging force to the plunger can be changed according to the amount of movement by a plurality of urging means having different urging forces or lengths. If changed stepwise, the amount of movement of the plunger can be changed stepwise as the electromagnetic force increases.

[0011]

A second aspect of the present invention is to electromagnetically open a flow path by moving a valve body to a valve opening side through a plunger by applying a constant voltage to a coil to excite the coil. In the on-off valve, (a) the plunger is divided into a plurality of pieces in the moving direction of the plunger, and the split plunger located at the tip on the valve closing side and the valve body are integrally moved to open and close the flow path, (B) a plurality of stoppers that respectively define moving ends of the plurality of split plungers on the valve closing side; and (c) urge the plurality of split plungers toward the valve closing side to abut the stopper. A plurality of urging means for holding the two in a state of being separated from each other and permitting the divided plungers on the valve closing side to move to the valve opening side with a smaller electromagnetic force.

[0012]

The second invention corresponds to an embodiment of the electromagnetic on-off valve of the first invention, and it is a case where the valve opening is increased stepwise, and a constant voltage is applied to the coil for excitation. Then, when the electromagnetic force is small and the temperature is high, the split plunger at the tip on the valve closing side is moved to the valve opening side against the biasing force of the biasing means, and by the second split plunger positioned by the stopper. By blocking the movement, the flow path is opened with a relatively small predetermined valve opening. When the electromagnetic force is large and the temperature is low, the second split plunger in addition to the split plunger at the tip on the valve closing side is moved to the valve opening side against the biasing force of the biasing means, so that a relatively large predetermined valve is opened. The flow path is opened at the opening. The valve opening is changed stepwise by the number of stages corresponding to the number of divisions of the plunger.
You can set the valve opening type.

[0013]

As described above, also in the electromagnetic on-off valve of the second invention, the valve opening becomes larger at low temperature than at high temperature due to the increase in electromagnetic force due to temperature decrease, so the temperature is low. Even when the fluidity of the fluid is poor, the same effect as that of the first aspect of the invention can be obtained such that the flow rate can be as high as that when the temperature is high and the fluidity is good. Moreover, in the present invention, since the valve opening degree is defined by the split plunger positioned by the stopper, for example, the valve opening degree is changed according to the temperature as compared with the case where the valve opening degree is changed by the balance between the urging force of the urging means and the electromagnetic force. As a result, a predetermined valve opening can be stably obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a vertical cross-sectional view of an electromagnetic opening / closing valve 10 according to an embodiment of the present invention, in which a base 14 and a core 16 are fixed to both ends of a cylindrical yoke 12 and the inside of them is fixed. Is a coil 20 in which a copper enamel wire is wound around the bobbin 18 at the base 14 and the core 1.
It is disposed so as to straddle 6 and substantially concentric with the yoke 12. The base 14 has a flange portion 22 fixed to the yoke 12.
And a cylindrical large-diameter portion 2 with a bottom that opens to the flange portion 22 side
4 and a bottomed cylindrical small-diameter portion 26 that is integrally provided on the bottom side of the large-diameter portion 24 and opens on the side opposite to the flange portion 22, and the bottomed circular hole of the small-diameter portion 26 is the first. A plurality of through holes provided in the peripheral wall of the port 28 and the large diameter portion 24 are respectively connected as a second port 30 to a hydraulic circuit of the vehicle automatic transmission or the like. A through hole 34 is provided in the bottom portion of the first port 28, that is, in the partition wall 32 between the large diameter portion 24 and the small diameter portion 26, and the poppet 36 as the valve body is on the valve closing side in the leftward direction in the drawing. By being moved and seated on the partition wall 32 so as to close the through hole 34,
While the flow path between the first port 28 and the second port 30 is closed, the poppet 36 is separated from the partition wall 32 in the right direction of the drawing, which is the valve opening side, so that the first port 28
A flow path between the second port 30 and the second port 30 is opened, and fluid such as hydraulic oil is allowed to flow. The partition wall 32 functions as a valve seat, and FIG. 1 shows a closed state in which the poppet 36 is seated on the valve seat.

A cylindrical sleeve 40 is fixedly provided on the inner peripheral side of the coil 20 so as to straddle the base 14 and the core 16 similarly to the coil 20.
A cylindrical first plunger 42 and a second plunger 44 are movable in the axial direction, that is, in the moving direction of the poppet 36 when opening and closing the flow path, in the left-right direction of the drawing by a predetermined predetermined dimension. It is installed in. The first plunger 42 and the second plunger 44 correspond to split plungers that are split in two in the moving direction, and are arranged in series on the center line of the electromagnetic opening / closing valve 10 and also the first plunger on the valve closing side. The poppet 36 is integrally fixed to the tip end surface of 42, that is, the surface opposite to the second plunger 44. Between the first plunger 42 and the second plunger 44, and the second plunger 44
A first compression coil spring 46 and a second compression coil spring 48, which urge each other in a direction in which they are separated from each other, are interposed between the core 16 and the core 16 as urging means. A circular hole having a bottom is formed in each of the facing surfaces of the first plunger 42 and the second plunger 44 and the facing surface of the second plunger 44 and the core 16, and the compression coil springs 46 and 48 are provided in the circular holes. Is installed in the
When they are brought close to each other against the spring force (biasing force), the facing surfaces are brought into contact with each other.

Since the core 16 is integrally fixed to the yoke 12, the second plunger 44 is biased toward the valve closing side by the second compression coil spring 48, and
The first plunger 42 is biased toward the valve closing side by the first compression coil spring 46, and the first plunger 42 has the poppet 36 with the partition wall 3 as is apparent from the valve closed state of FIG.
It is held at the moving end on the valve closing side which is seated at 2. The second plunger 44 has a larger diameter than the first plunger 42, and the inner peripheral surface of the sleeve 40 is also divided into a large diameter portion and a small diameter portion according to their diameter dimensions. It is positioned at the moving end on the valve closing side by being brought into contact with the step portion 50 on the inner peripheral surface, and the first plunger 42 and the core 16
Predetermined gaps are formed on both sides. The partition wall 32 that defines the moving end of the first plunger 42 on the valve closing side and the step portion 50 that defines the moving end of the second plunger 44 on the valve closing side each correspond to a stopper.

On the other hand, when a voltage is applied to the coil 20 to excite it, an electromagnetic force is generated, and between the core 16 and the second plunger 44, between the second plunger 44 and the first plunger 4.
An attraction force based on an electromagnetic force acts between the two and the attraction force overcomes the spring force of the compression coil springs 46 and 48, and the plungers 42 and 44 move toward the valve opening side. The flow path is opened. In that case, coil 1
Since 2 is a copper enameled wire, the electric resistance decreases as the temperature decreases, and when a constant voltage is applied, the current value increases and the electromagnetic force, and further the attractive force increases. Specifically, when the electric resistance of the hydraulic circuit of the vehicle automatic transmission at a steady temperature of 60 ° C. is, for example, 15 Ω, the electric resistance at −30 ° C. is about 10 Ω, which is a constant voltage of 12 V. When applied, the current values are 0.8 A and 1.2 A, respectively. Further, since the electromagnetic force, that is, the magnetomotive force, is the number of turns of the coil 20 multiplied by the current value, the electromagnetic force increases as the current value increases, and the attraction force also increases accordingly. The attraction force is proportional to the square of the electromagnetic force and is proportional to the area of the suction surface, and is inversely proportional to the square of the gap (air gap). Therefore, even with the same electromagnetic force, the force between the core 16 and the second plunger 44 is increased. Is different from the suction force between the second plunger 44 and the first plunger 42.

The first compression coil spring 4
The spring force (preload) of 6 causes the first plunger 42 to move toward the valve opening side according to the suction force even at a predetermined high temperature where the electromagnetic force is relatively small, and as shown in FIG.
It is set so as to be positioned at the first valve opening position where it abuts against. Further, the spring force (preload) of the second compression coil spring 48 overcomes the suction force at the predetermined high temperature and holds the second plunger 44 in contact with the step portion 50, but the electromagnetic force is compared. The second plunger 44 is set to move toward the valve opening side in accordance with the suction force at a predetermined low temperature, which is relatively large, and is brought into contact with the core 16 as shown in FIG. At this time, the first plunger 42 is moved to the valve opening side integrally with the second plunger 44, and is positioned at the second valve opening position shown in FIG. That is, when the temperature is low, the valve opening is larger than that at the time of high temperature, the flow cross-sectional area is large, and the fluid easily flows. Even in this case, it is possible to secure the same flow rate as that at high temperature with good fluidity. The gap (air gap) between the first plunger 42 and the second plunger 44, and the gap (air gap) between the second plunger 44 and the core 16 are
In consideration of the change in fluidity of the fluid, the flow rate is set to be as high as possible at high temperature and at low temperature as described above.

Since whether or not the plungers 42 and 44 move is determined by the relationship between the spring force and the suction force, as a result, the plungers 42 and 44 resist the spring force at a predetermined temperature.
If the plunger 42,
It is also possible to adjust by changing the area of the suction surface of 44. Further, when setting the spring force, strictly speaking, it is necessary to consider the fluid pressure acting on the valve opening side of the first plunger 42.

A specific description will be given of a case where the solenoid opening / closing valve 10 is used in a hydraulic circuit of an automatic transmission for a vehicle. The temperature when the fluidity of the working oil is good during normal running after the engine is warmed up, for example, 60 A temperature of about ℃ is set to the predetermined high temperature, and in that state, the first compression coil spring 46 is moved so that the first plunger 42 can be moved to the first valve opening position.
Set the spring force of. Further, at the beginning of starting the engine, the fluidity of the hydraulic oil is poor and the temperature is at a relatively low temperature, for example, -3.
The temperature of about 0 ° C. is set to the predetermined low temperature, and in this state, the spring force of the second compression coil spring 48 is set so that the first plunger 42 is moved to the second valve opening position. That is, the spring force of the first compression coil spring 46 is set so that the first plunger 42 moves to the valve opening side regardless of the temperature when a constant voltage is applied to the coil 20, and the second compression coil Regarding the spring force of the spring 48, the fluidity of the hydraulic oil deteriorates in consideration of a predetermined temperature lower than 60 ° C. and higher than −30 ° C., specifically, the fluidity of the hydraulic oil and the temperature. The second plunger 44 is set to move to the valve opening side at a predetermined temperature or higher higher than the temperature.

As described above, in the electromagnetic on-off valve 10 of the present embodiment, when a constant voltage is applied to the coil 20 to excite it, at a predetermined high temperature where the electromagnetic force is small, the first plunger as shown in FIG. 42 is positioned at the first valve opening position, and the flow path is opened with a relatively small valve opening, while at a predetermined low temperature when the electromagnetic force is large, the first plunger 42 opens the second valve as shown in FIG. The flow path is opened with a relatively large valve opening. Therefore, even when the temperature is low and the fluidity is poor, it is possible to secure the same flow rate as when the temperature is high and the fluidity is good.

Further, since only the first plunger 42 is moved when the temperature is high and the movement amount of the poppet 36 is small,
The responsiveness when opening and closing the valve is excellent, and even when the application time of the voltage, that is, the opening time of the valve is duty controlled, the pulsation of the flow rate and the pressure due to the opening and closing can be kept as small as the conventional one.

Further, in order to increase the valve opening degree by utilizing the increase of the electromagnetic force due to the temperature decrease, a correction value for measuring the temperature of the fluid using a temperature sensor or correcting the duty ratio according to the fluid temperature is set. There is no need for special means or control for changing the valve opening degree according to temperature, such as storing in a data map, and the entire apparatus including the control system for opening and closing the valve can be configured simply and inexpensively.

Further, since the first plunger 42 is positioned at the first valve opening position or the second valve opening position and the valve opening degree is set in two steps, for example, the balance between the urging force of the urging means and the electromagnetic force. As compared with the case where the valve opening degree is changed by, the predetermined valve opening degree can be stably obtained according to the temperature.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above-described embodiment, the case where the solenoid opening / closing valve 10 is used in the hydraulic circuit of the automatic transmission for a vehicle has been described as an example, but it is needless to say that the solenoid opening / closing valve 10 can be used in various other fields and the valve opening is changed. Compressed coil spring 4
It can be set as appropriate by changing the relationship between the spring force of 8 and the suction force.

Further, in the above embodiment, two kinds of valve opening are obtained, but the valve opening can be changed in three or more steps by dividing the plunger into three or more. Even if there is only one plunger, the urging force for the plunger is changed stepwise according to the moving amount by a plurality of urging means having different urging forces or lengths, so that the valve opening degree can be set in two steps or in three or more steps. It is also possible to change with.

Further, although the compression coil springs 46 and 48 are used as the urging means in the above-mentioned embodiment, not only other springs such as the tension coil spring but also other urging members such as an elastic body such as rubber or pressure air are used. It is also possible to use means.

In the above embodiment, the first compression coil spring 46 is interposed between the plungers 42 and 44. However, the first compression coil spring 46 is interposed between the first plunger 42 and the sleeve 40 or the core 16. The spring 46 can also be provided.

Although the poppet 36 is used as the valve element in the above-mentioned embodiment, other valve elements such as spools can be used. When the spool is used, the first plunger 42 is closed. There will be a stopper for positioning.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an electromagnetic opening / closing valve according to an embodiment of the present invention, showing a valve closed state.

FIG. 2 is a vertical cross-sectional view showing a valve open state of the electromagnetic opening / closing valve of FIG. 1 at a high temperature.

FIG. 3 is a vertical cross-sectional view showing a valve open state of the electromagnetic opening / closing valve of FIG. 1 at a low temperature.

[Explanation of symbols]

 10: electromagnetic on-off valve 20: coil 32: partition wall (stopper) 36: poppet (valve body) 42: first plunger (split plunger) 44: second plunger (split plunger) 46: first compression coil spring (biasing means) ) 48: Second compression coil spring (biasing means) 50: Step (stopper)

Claims (2)

[Claims] 1. An electromagnetic on-off valve that opens a flow path by moving a valve element to a valve opening side through a plunger by applying a constant voltage to a coil to excite the electromagnetic field due to a decrease in temperature of the coil. Based on the increase in power,
The amount of movement of the plunger toward the valve opening side is increased against the urging force of the urging means for urging the plunger toward the valve closing side so that the valve opening degree becomes larger at low temperature than at high temperature. An electromagnetic on-off valve characterized by. 2. An electromagnetic on-off valve that opens a flow path by moving a valve body to a valve-opening side through a plunger by applying a constant voltage to a coil to excite the plunger in the moving direction of the plunger. Is divided into a plurality of parts to integrally open and close the flow path by integrally moving the split plunger located at the tip on the valve closing side and the valve element, while defining the moving ends of the plurality of split plungers on the valve closing side. The plurality of stoppers and the plurality of split plungers are urged toward the valve closing side to abut against the stoppers and are held in a state of being separated from each other, and the electromagnetic force smaller than that of the split plungers on the valve closing side is used. An electromagnetic opening / closing valve, comprising: a plurality of biasing means that allow movement toward the valve opening side.