JP7775768B2 - Solenoid Device - Google Patents

Description

This disclosure relates to a solenoid device that can maintain a fully open position and a fully closed position.

Patent Document 1 discloses a solenoid device that is driven by two magnets with opposing polarities. The solenoid in Patent Document 1 uses a non-magnetic material for the plunger shaft, making it impossible to utilize magnetic attractive force on the plunger shaft. As a result, the magnetic attractive force remains constant regardless of the position of the plunger shaft. With this structure, a large magnetic attractive force is required when switching the position of the plunger shaft, which necessitates a larger coil.

JP 2011-82319 A

The objective of this disclosure is to reduce the power consumption when switching positions and to miniaturize the coil size.

The first aspect of the present disclosure is a solenoid device comprising: a coil that forms a magnetic circuit when energized; a moving core made of a magnetic material that is placed within the magnetic circuit of the coil; a first permanent magnet that is placed on one side of the moving core; a first member made of a magnetic material that attracts the moving core with the magnetic force of the first permanent magnet when the moving core is in a first position; a second permanent magnet that is placed on the other side of the moving core; and a second member made of a magnetic material that attracts the moving core with the magnetic force of the second permanent magnet when the moving core is in a second position.

The first solenoid device of the present disclosure includes a stator core made of a magnetic material, in which a first magnetic constriction portion is formed on one surface of a moving core and a second magnetic constriction portion is formed on the other surface of the moving core. When the moving core is in the first position, a magnetic gap exists between the second permanent magnet and the moving core and the second magnetic constriction portion, and when the moving core is in the second position, a magnetic gap exists between the first permanent magnet and the moving core and the first member.

In the first aspect of the present disclosure, when the moving core is held in either the first or second position, no current is passed through the coil. When moving the moving core from the first position toward the second position, current is passed through the coil, and the moving core is attracted by the magnetic gaps between the second member and the second permanent magnet and between the moving core and the stator core. In addition, when moving the moving core from the second position toward the first position, current is passed through the coil, and the moving core is attracted by the magnetic gaps between the first member and the first permanent magnet and between the moving core and the stator core.

According to the first aspect of the present disclosure, the moving core can be moved in the first or second direction by the magnetic gap between the first magnetic constriction portion of the stator core and the first permanent magnet and moving core, and the magnetic gap between the second magnetic constriction portion of the stator core and the second permanent magnet and moving core. The state of being held in either the first or second position is maintained by the first or second permanent magnet, and no current is passed through the coil.

In a second aspect of the present disclosure, the magnetic pole of the first permanent magnet facing one side of the moving core and the magnetic pole of the second permanent magnet facing the other side of the moving core have the same polarity , and the direction of the magnetic flux of the first permanent magnet and the direction of the magnetic flux of the second permanent magnet are opposite . Then, when the moving core is moved from the first position to the second position, current is passed through the coil in a first direction, and the direction of the magnetic flux generated by the current passing through the coil in the first direction between the first permanent magnet and the first magnetic constriction of the stator core is made opposite to the direction of the magnetic flux of the first permanent magnet, thereby repelling the direction of the magnetic force, and the direction of the magnetic flux generated by the current passing through the coil in the first direction between the second permanent magnet and the second magnetic constriction of the stator core is made the same to match the direction of the magnetic force.

Conversely, when the moving core is moved in a direction from the second position toward the first position, current is passed through the coil in a second direction opposite to the first direction, and the direction of the magnetic flux generated by the current passing through the coil in the second direction between the second permanent magnet and the second magnetic constriction portion of the stator core is opposite to the direction of the magnetic flux of the second permanent magnet, thereby repelling the direction of the magnetic force, and the direction of the magnetic flux generated by the current passing through the coil in the second direction between the first permanent magnet and the first magnetic constriction portion of the stator core is the same as the direction of the magnetic flux of the first permanent magnet, thereby aligning the direction of the magnetic force.

According to the second aspect of the present disclosure, the attractive and repulsive forces of the first and second permanent magnets can be utilized when moving the moving core from the second position toward the first position, and when moving the moving core from the first position toward the second position. This makes it possible to compensate for the magnetic force generated in the coil when current is applied. As a result, the coil can also be made smaller.

The third solenoid device of the present disclosure further includes a valve housing having an inlet passage through which fluid flows, an outlet passage through which fluid flows, and a valve seat formed between the outlet passage and the inlet passage, and a valve that moves in response to movement of the moving core, abutting and disengaging from the valve seat to control the flow of fluid from the inlet passage to the outlet passage.

In the third aspect of the present disclosure, when the moving core is held in the first position, the valve is either in contact with or disengaged from the valve seat, and when the moving core is held in the second position, the valve is either in contact with or disengaged from the valve seat. In the third aspect of the present disclosure, a solenoid device can be used to open and close the valve.

FIG. 4 is a cross-sectional view showing a state in which the solenoid device is in a first position. FIG. 4 is a cross-sectional view showing a state in which the solenoid device is in a second position. 4 is a cross-sectional view showing the magnetic flux when the solenoid device moves from a first position to a second position. FIG. 4 is a cross-sectional view showing the magnetic flux when the solenoid device moves from the second position to the first position. FIG. 5A and 5B are diagrams illustrating the relationship between the magnetic force and stroke of a solenoid device.

An embodiment of the present disclosure is a solenoid device 100 shown in Figure 1, which includes a coil 110. The coil 110 is made by winding a large number of turns of enamel-coated copper wire around a coil bobbin made of resin such as polyphenylene sulfide resin (PPS). A stator core 120 is disposed on the inner periphery of the coil 110. The stator core 120 is made of a magnetic material, such as carbon steel.

The outer periphery of the coil 110 is covered by an outer shell 130 made of resin such as polyphenylene sulfide resin (PPS). The outer shell 130 is formed integrally with a connector 131. A pair of terminals 136 are embedded and molded within the connector 131, and the pair of terminals 136 are connected to the positive and negative sides of the coil 110, respectively. The terminal designated by reference numeral 134 is a magnetic terminal of the first magnetic sensor 135, and the terminal designated by reference numeral 133 is a magnetic terminal of the second magnetic sensor 137.

The stator core 120, which is located inside the coil 110, has a cylindrical shape, and the moving core 140 is located inside the cylindrical shape. Therefore, the moving core 140 is movable within the stator core 120. The moving core 140 is made of a magnetic material such as cold-rolled steel plate (SPCE). A disk-shaped first permanent magnet 151 is bonded to one surface of the moving core 140 (the upper end surface in Figure 1). A ring-shaped second permanent magnet 152 is bonded to the other surface of the moving core 140 (the lower end surface in Figure 1).

The magnetic pole of the first permanent magnet 151 facing one surface 141 of the moving core 140 and the magnetic pole of the second permanent magnet 152 facing the other surface 142 of the moving core 140 have the same polarity. In the example of Figures 1 and 2, the top surface of the first permanent magnet 151 is an S pole and the bottom surface (the surface facing one surface 141 of the moving core 140) is an N pole. On the other hand, the top surface of the second permanent magnet 152 (the surface facing the other surface 142 of the moving core 140) is an N pole and the bottom surface is an S pole.

A yoke 125 is arranged from the outer periphery of the coil 110 to the portion facing the first permanent magnet 151. The yoke 125 is also made of a magnetic material such as iron. Therefore, the first permanent magnet 151 can be attracted to the yoke 125 by magnetic force. In this disclosure, the portion of the yoke 125 facing the first permanent magnet 151 is the first member 153.

The bottom of the cylindrical portion of the stator core 120 also faces the second permanent magnet 152, as shown in FIG. 2, and the second permanent magnet 152 can be attracted to the stator core 120 by magnetic force. In the present disclosure, the bottom of the cylindrical portion of the stator core 120 that faces the second permanent magnet 152 serves as the second member 154.

The middle section of the cylindrical portion of the stator core 120 is formed with a thin wall. Therefore, a first magnetic restricting portion 121 is formed from this middle section toward one surface 141 of the moving core 140. Conversely, a second magnetic restricting portion 122 is formed from the middle section toward the other surface 142 of the moving core 140. The moving core 140, first permanent magnet 151, and second permanent magnet 152 are held within the cylindrical portion of the stator core 120.

The solenoid device 100 is configured as described above. This solenoid device 100 is coupled to the valve section 200. The valve section 200 is formed by the valve housing 210. The valve housing 210 is made of a non-magnetic material, such as an aluminum alloy.

The valve housing 210 is formed with an inlet passage 222 through which various fluids flow depending on the application. As an example, it can be used to switch the refrigerant flow in a heat pump system for a vehicle air conditioning system. The end of the inlet passage 222 is tapered. The valve housing 210 is formed with a valve chamber 225, which is connected to the inlet passage 222. The upper part of the valve housing 210 is joined to the solenoid device 100. The valve housing 210 is formed with an outlet passage 228 through which the inlet fluid flows out.

A valve chamber 225 is formed in the valve housing 210 between the inlet passage 222 and the outlet passage 228. Facing this valve chamber 225 is a ring-shaped valve seat 229 that communicates with the outlet passage 228. The valve element 214 is positioned in the valve chamber 225 facing the valve seat 229.

The valve body 214 has a valve body portion 217. The upper end of the valve body portion 217 is fixed to the moving core 140. Therefore, the valve body 214 moves integrally with the moving core 140. A central hole is formed in the center of the valve body portion 217.

A sheet 218 made of a rubber material such as ethylene propylene glycol (EPDM) is adhered to the lower end of the valve element 214 at a location facing the valve seat 229. When the valve element 214 is seated on the valve seat 229, the valve seat 229 is sealed by the sheet 218. This blocks the flow of fluid between the valve element 214 and the valve seat 229.
The valve section 200 and solenoid device 100 configured as described above have the stator core 120 of the solenoid device 100 mounted on top of the valve housing 210. The valve housing 210, made of a non-magnetic material, and the outer shell 130, made of resin, are joined by screwing or the like.

Next, the operation of the solenoid device 100 of the present disclosure will be described. As shown in Figure 1, the state in which the moving core 140 is attracted to the first member 153 by the magnetic attractive force of the first permanent magnet 151 is referred to as the first position. And as shown in Figure 2, the state in which the moving core 140 is attracted to the second member 154 by the magnetic force of the second permanent magnet 152 is referred to as the second position.

The first position is maintained by the magnetic attraction of the first permanent magnet 151, with no current passing through the coil 110. In this first position, the valve disc 214 is also in its first position and is separated from the valve seat 229. Therefore, fluid that flows into the valve chamber 225 from the inlet passage 222 flows from the valve seat 229 to the outlet passage 228. In addition, in this first position, fluid also flows through the central hole formed in the center of the valve body 217. This allows the fluid to flow out without current passing through the coil 110.

The second position is maintained in the same manner. That is, the coil 110 is not energized, and is maintained in contact with the second member solely by the magnetic attraction force of the second permanent magnet 152. In this second position, the valve disc 214 is also in the second position and is seated on the valve seat 229. Therefore, fluid that flows from the inlet passage 222 into the valve chamber 225 is blocked by the valve disc 214 and does not flow into the outlet passage 228. This allows the fluid to be blocked without energizing the coil 110.

When moving from the first position to the second position, as shown in Figure 3, current is passed through the coil 110 in the first direction, and the leakage magnetic flux between the second magnetic restrictor portion 122 of the stator core 120 and the second permanent magnet 152 and moving core 140 attracts the moving core 140. The magnetic flux at this time is oriented in a direction that repels the first permanent magnet 151. Conversely, the magnetic flux is oriented in a direction that attracts the second permanent magnet 152. Therefore, the magnetic force required to move the moving core 140 can be compensated for by the first permanent magnet 151 and the second permanent magnet 152. In other words, it is possible to reduce the size of the coil 110 required to move the moving core 140.

When the moving core 140 moves to the second position, as described above, the power supply to the coil 110 is terminated, and the second position is maintained by the second permanent magnet 152. When moving the moving core 140 from the second position toward the first position, the coil 110 is powered, and leakage magnetic flux between the first magnetic restricting portion 121 of the stator core 120 and the first permanent magnet 151 and moving core 140 attracts the moving core 140. The power supply to the coil 110 in this case is in a second direction, opposite to the first direction. Therefore, as shown in FIG. 4, the magnetic flux is directed in a direction of mutual attraction in the first permanent magnet 151 and a direction of mutual repulsion in the second permanent magnet 152. Therefore, even when moving the moving core 140 from the second position toward the first position, the magnetic force required to move the moving core 140 can be compensated for by the first permanent magnet 151 and the second permanent magnet 152.

Note that Figures 3 and 4 show the magnetic circuit diagrammatically, and the portion of the moving core 140 that connects to the valve body 214 is omitted. However, as shown in Figures 3 and 4, it is possible for the first member 153 to be a separate member from the yoke 125. Similarly, it is also possible for the second member 154 to be a separate member from the stator core 120. If the stator core 120 is cylindrical with a closed upper portion, it is also possible for the first member 153 to be formed from the stator core 120.

Figure 5 is an explanatory diagram illustrating the position and current flow state of the moving core 140 described above. Point D in Figure 5 indicates the state in which the moving core 140 is held in the first position. The attractive force in this state is the magnetic force of the first permanent magnet 151 attracting the first member 153. Movement from the first position to the second position is shown by line F. In this state, a voltage is applied to the coil 110 in the first direction. In Figure 5, the first direction is represented by -. Point G is the state in which the second position is reached. In this state at point G, the second position is maintained by the excitation force of the coil 110.

The state when the application of the voltage in the first direction to coil 110 ends at the second position is point H. After point G, the stroke at the second position is maintained at point H by the attractive force of second permanent magnet 152. Movement from the second position to the first position is shown by line B. In the state of line B, a voltage in the second direction is applied to coil 110. In Figure 5, the second direction is represented by a +. The state when the first position is reached is point C. The state at point C is the opposite of point G, where the first position is maintained by the excitation force of coil 110. The state when the application of the voltage in the second direction to coil 110 ends at the first position is point D, and thereafter the initial point D is maintained by the attractive force of first permanent magnet 151.

As mentioned above, whether the moving core 140 is maintained in the first position or the second position, the coil 110 is not energized. Therefore, it is difficult to determine whether the coil 110 is in the first position or the second position based on the energization of the coil 110 without using a memory or the like. In this example, the position of the moving core 140 is detected by the first magnetic sensor 135.

The first magnetic sensor 135 is positioned to detect the magnetic force of the first permanent magnet 151 when the first permanent magnet 151 is in the first position. The first magnetic sensor 135 is a reed switch, electromagnetic pickup sensor, or Hall sensor that outputs a signal when it detects magnetic force. The first magnetic sensor 135 is magnetically shielded from the magnetic field of the coil 110. More specifically, the magnetic field of the coil 110 flows through the moving core 140 and yoke 125, and does not leak into the resin outer casing 130, or if any magnetic leakage occurs, it is very small.

In contrast, as shown in Figure 3, the magnetic field of the first permanent magnet 151 leaks toward the outer casing 130 separately from the magnetic field of the coil 110. The first magnetic sensor 135 detects this leaking magnetic flux from the first permanent magnet 151. Therefore, if a signal from the first magnetic sensor 135 is detected, it can be confirmed that the moving core 140 and valve body 214 are in the first position. In other words, if no signal is detected from the first magnetic sensor 135, the moving core 140 and valve body 214 are in the second position.

The second magnetic sensor 137 is positioned to detect the magnetic force of the first permanent magnet 151 when the first permanent magnet 151 is in both the first position and the intermediate position. As mentioned above, the magnetic field of the first permanent magnet 151 leaks out to the outer casing 130 most strongly in the first position shown in Figure 3. Conversely, in the second position shown in Figure 4, the magnetic field of the first permanent magnet 151 hardly leaks out to the outer casing 130. The second magnetic sensor 137 is positioned in an area where the magnetic field of the first permanent magnet 151 can be detected in both the first position and the intermediate position. Like the first magnetic sensor 135, the second magnetic sensor 137 is also hardly affected by the magnetic field of the coil 110. The second magnetic sensor 137 is also a reed switch, magnetic pickup sensor, or Hall sensor that outputs a signal when it detects magnetic force; in this example, a Hall sensor is used. If a signal from the second magnetic sensor 137 is detected, it can be confirmed that the moving core 140 and valve body 214 are in either the first position or the intermediate position.

The first magnetic sensor 135 and second magnetic sensor 137 enable the position of the solenoid device 100 (moving core 140) to be detected. The first magnetic sensor 135 detects the magnetic force of the first permanent magnet 151 when in the first position. Therefore, when the moving core 140 and valve body 214 are held in the first position, the first magnetic sensor 135 detects the magnetic force "on." In this first position, the second magnetic sensor 137 also detects the magnetism of the first permanent magnet 151 and turns "on."

Conversely, when the moving core 140 and valve body 214 are held in the second position, the first magnetic sensor 135 does not detect the magnetism of the first permanent magnet 151 and is "off," and the second magnetic sensor 137 also does not detect the magnetism and is "off." Furthermore, when the moving core 140 and valve body 214 are in the intermediate position, the first magnetic sensor 135 does not detect the magnetism of the first permanent magnet 151 and is "off," but the second magnetic sensor 137 detects the magnetism of the first permanent magnet 151 and is "on."

The position of the valve disc 214 can be confirmed from the fluid flow. If there is a discrepancy between the fluid flow and the signals from the first magnetic sensor 135 and second magnetic sensor 137, an abnormality in the solenoid device 100 can be detected. Furthermore, the current position of the solenoid device 100 can also be estimated. For example, when the solenoid device 100 is in the first position, the first magnetic sensor 135 should detect the magnetism of the first permanent magnet 151 and be "on," but instead it outputs an "off" signal. In this case, if the second magnetic sensor 137 is "on," it can be inferred that the device is in the intermediate position, and if the second magnetic sensor 137 is "off," it can be inferred that the device is stuck in the second position. In this case, the coil 110 can be energized in the first direction to return the moving core 140 and valve disc 214 to the first position.

When in the second position, neither the first magnetic sensor 135 nor the second magnetic sensor 137 should detect the magnetic field of the first permanent magnet 151 and should output an "off" signal. However, if both the first magnetic sensor 135 and the second magnetic sensor 137 output an "on" signal, it can be assumed that the moving core 140 and valve body 214 are stuck in the first position. In that case, the moving core 140 and valve body 214 can be returned to the second position by energizing the coil 110 in the second direction, in the opposite direction to the above.

When the moving core 140 is in an intermediate position moving from the first position to the second position, or conversely, when it is in an intermediate position moving from the second position to the first position, the second magnetic sensor 137 turns "on." This makes it possible to determine whether the position has been switched reliably.

As explained above, the first and second positions are maintained by the first permanent magnet 151 and the second permanent magnet 152. Therefore, there is a risk that the moving core 140 may move to the second position while it is originally in the first position. In this way, it is possible that the moving core 140 may move to a position different from its intended position due to external vibrations or other influences. In this case, a signal is again sent to the coil 110 to move the moving core 140 to its intended position.

In the above disclosure, the valve housing 210 is constructed as a single unit, but it may also be separated into an upper body and a lower body. In this case, the two components are fixed using a fixing method such as welding, bolting, or clipping. The valve housing 210 may also be constructed from three or more components. In the above example, the moving core 140 and the valve element 214 are connected by a rod 215, but the moving core 140 may also be used as the valve element 214.

In the above example, the solenoid device 100 was used as a valve that opens and closes the valve seat 229, but it may also be used for various actuators. For example, it can be used to operate driven objects such as a shade that controls the light distribution between low and high in a discharge headlamp, a leveler that adjusts the direction of illumination up and down, an AFS that adjusts the direction of illumination left and right, and a shift lever lock device in a vehicle equipped with an automatic transmission (AT vehicle).

In addition, in the above example, the first magnetic sensor 135 and the second magnetic sensor 137 were used to detect abnormalities in the solenoid device 100, but it is also possible to use only one magnetic sensor and eliminate the first magnetic sensor 135 or the second magnetic sensor 137. Furthermore, if the position of the moving core 140 is estimated from the current flow record of the coil 110, or if detecting the position of the moving core 140 is not necessary, it is also possible to eliminate both magnetic sensors.

In addition, in the above example, the magnetic forces of the first permanent magnet 151 and the second permanent magnet 152 were used as an auxiliary force when switching from the first position to the second position or from the second position to the first position. However, in the present disclosure, it is not necessary to use the magnetic forces of the first permanent magnet 151 and the second permanent magnet 152 as an auxiliary force. Therefore, the magnetic pole of the first permanent magnet 151 facing one surface 141 of the moving core 140 and the magnetic pole of the second permanent magnet 152 facing the other surface 142 of the moving core 140 do not need to have the same polarity.

The disclosure in this specification and drawings is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations thereon that may be made by those skilled in the art.

100 Solenoid device 110 Coil 140 Moving core 151 First permanent magnet 152 Second permanent magnet 153 First member 154 Second member 214 Valve body 222 Inlet passage 228 Outlet passage 229 Valve seat

Claims (3)

a coil that forms a magnetic circuit when energized;
a moving core made of a magnetic material and disposed in the magnetic circuit of the coil;
a first permanent magnet disposed on one surface of the moving core;
a first member made of a magnetic material that attracts the moving core with the magnetic force of the first permanent magnet when the moving core is located at a first position;
a second permanent magnet disposed on the other surface of the moving core;
a second member made of a magnetic material that attracts the moving core with the magnetic force of the second permanent magnet when the moving core is located at the second position;
a stator core made of a magnetic material, in which a first magnetic constriction portion is formed on one surface side of the moving core and a second magnetic constriction portion is formed on the other surface side of the moving core, so that when the moving core is located at the first position, a magnetic gap exists between the second permanent magnet and the moving core and the second member, and when the moving core is located at the second position, a magnetic gap exists between the first permanent magnet and the moving core and the first member;
A solenoid device having:
When the moving core has finished moving and is held at either the first position or the second position, the coil is not energized,
When the moving core is moved in a direction from the first position toward the second position, the coil is energized to attract the moving core by leakage magnetic flux between the second magnetic restricting portion of the stator core and the second permanent magnet and the moving core,
When the moving core is moved in a direction from the second position toward the first position, the coil is energized, and the moving core is attracted by leakage magnetic flux between the first magnetic restricting portion of the stator core and the first permanent magnet and the moving core.
A solenoid device characterized by: a magnetic pole of the first permanent magnet facing one surface of the moving core and a magnetic pole of the second permanent magnet facing the other surface of the moving core have the same polarity, and a direction of magnetic flux of the first permanent magnet and a direction of magnetic flux of the second permanent magnet are opposite to each other;
When the moving core is moved in a direction from the first position toward the second position, current is passed through the coil in a first direction, and a direction of magnetic flux generated by the current passing through the coil in the first direction between the first permanent magnet and the first magnetically constricted portion of the stator core is made opposite to a direction of magnetic flux of the first permanent magnet, and a direction of magnetic flux generated by the current passing through the coil in the first direction between the second permanent magnet and the second magnetically constricted portion of the stator core is made the same as a direction of magnetic flux of the second permanent magnet,
2. The solenoid device according to claim 1, wherein, when the moving core is moved in a direction from the second position toward the first position, current is passed through the coil in a second direction opposite to the first direction, so that the direction of magnetic flux generated by the current passing through the coil in the second direction between the second permanent magnet and the second magnetically constricted portion of the stator core is opposite to the direction of magnetic flux of the second permanent magnet, and the direction of magnetic flux generated by the current passing through the coil in the second direction between the first permanent magnet and the first magnetically constricted portion of the stator core is the same as the direction of magnetic flux of the first permanent magnet. The solenoid device
a valve housing having an inlet passage through which a fluid flows, an outlet passage through which the fluid flows out, and a valve seat formed between the outlet passage and the inlet passage;
a valve that moves in response to movement of the moving core to come into contact with and separate from the valve seat to control the flow of fluid from the inlet passage to the outlet passage,
3. The solenoid device according to claim 1, wherein when the moving core is held at the first position, the valve is in one of abutting and disengaging states with respect to the valve seat, and when the moving core is held at the second position, the valve is in the other of abutting and disengaging states with respect to the valve seat.