JP2021148147A - Electromagnetic buffer - Google Patents

Abstract

To provide an electromagnetic buffer capable of adjusting a height of a vehicle and preventing filed thermal demagnetization.SOLUTION: An electromagnetic buffer D comprises: an outer tube 1; a cylindrical armature 2 fixed to the inner periphery of the outer tube 1; a rod 3 with a field 4 that is axially movable with respect to the outer tube 1 and is inserted into the armature 2; an annular spring receiver 5 provided on the outer periphery of the outer tube 1, and supporting one end of a suspension spring 6; and a jack J that has a jack chamber R on the outer periphery of the armature 2 in the outer tube 1, and can move the spring receiver 5 in the axial direction with respect to the outer tube 1 by increasing or decreasing an amount of liquid in the jack chamber R.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electromagnetic shock absorber.

The electromagnetic shock absorber includes, for example, an armature having a cylinder, a large number of annular iron cores provided in the cylinders arranged in an axial direction at intervals, and an annular winding mounted between the iron cores, and an armature among the armatures. It is provided with a rod inserted in the circumference and a large number of permanent magnets mounted on the outer circumference of the rod so that S poles and N poles appear in the axial direction.

The electromagnetic shock absorber configured in this way is used by being interposed between the vehicle body and the wheels in the vehicle, and generates thrust by energizing the winding and attracting the permanent magnet provided on the rod. This thrust is used as a damping force that suppresses vibration of the vehicle body and wheels.

The armature in the electromagnetic shock absorber generates heat by energization during use of the electromagnetic shock absorber, but since it is housed in a sealed cylinder, the temperature inside the cylinder rises. In this way, when the electromagnetic shock absorber is used for a long time, the temperature inside the cylinder rises, so when the permanent magnet mounted on the rod is exposed to a high temperature and the temperature of the permanent magnet reaches a temperature at which it is thermally demagnetized, The damping force of the electromagnetic shock absorber is reduced.

Therefore, in the conventional electromagnetic shock absorber, in order to dissipate the heat generated by the armature to the atmosphere, heat radiation fins are provided in a part of the cylinder to prevent thermal demagnetization of the permanent magnet (for example, Patent Document 1). reference).

Japanese Unexamined Patent Publication No. 2009-136118

In the conventional electromagnetic shock absorber, heat dissipation is improved by installing heat dissipation fins in the cylinder and suppressing the temperature inside the cylinder from rising due to the heat generated by the armature, but heat dissipation is achieved only by installing the heat dissipation fins. There is a possibility that the permanent magnet will be demagnetized due to insufficient heat.

In addition, unlike hydraulic shock absorbers, conventional electromagnetic shock absorbers can actively exert thrust without expansion and contraction, so the thrust that is exerted is borne by the suspension springs interposed between the vehicle body and the wheels in the vehicle. It can bear a part of the weight of the car body. Therefore, in the conventional electromagnetic shock absorber, the height (vehicle height) of the vehicle body can be adjusted by changing the ratio of the vehicle body weight borne by the suspension spring by adjusting the thrust. However, when trying to maintain the vehicle height by the thrust of the electromagnetic shock absorber, the electromagnetic shock absorber continues to supply the armature with the current necessary to maintain the vehicle height, causing the armature to generate heat and the permanent magnet. It causes a temperature rise. Therefore, it is difficult to adjust the vehicle height with a conventional electromagnetic shock absorber.

Therefore, an object of the present invention is to provide an electromagnetic shock absorber capable of adjusting the vehicle height and preventing thermal demagnetization of the field magnetism.

In order to achieve the above object, the electromagnetic shock absorber of the present invention includes an outer tube, a tubular armature fixed to the inner circumference of the outer tube, and an armature that is movable in the axial direction with respect to the outer tube. A rod having a field to be inserted into the child, an annular spring receiver provided on the outer periphery of the outer tube to support one end of the suspension spring, and a jack chamber on the outer periphery of the armature in the outer tube. It is configured with a jack that can move the spring receiver in the axial direction with respect to the outer tube by increasing or decreasing the amount of liquid in.

The electromagnetic shock absorber configured in this way not only suppresses the vibration of the vehicle body by the generation of thrust, but also supplies and discharges liquid to the jack chamber with a jack when adjusting the vehicle height, so it is possible to maintain the vehicle height. There is no need to energize the armature. In addition, a jack chamber is provided on the outer periphery where the armature of the outer tube is provided, and the parts mounted on the outer periphery of the outer tube in the jack can increase the surface area and release the heat of the armature to the atmosphere, and the liquid in the jack chamber can be released to the atmosphere. If the armature is circulated, the liquid becomes a cooling liquid and takes away the heat of the armature to cool the armature.

In addition, the jack in the electromagnetic shock absorber is connected to the tank that is communicated to the jack chamber via the discharge path to store the liquid, the pump that can suck the liquid from the tank and supply the liquid to the jack chamber through the supply path, and the supply path. It may have a check valve provided to block only the flow of liquid from the jack chamber to the pump, and a valve element provided in the discharge path to adjust the amount of liquid in the jack chamber. According to the electromagnetic shock absorber configured in this way, the liquid can be circulated between the jack chamber and the tank while maintaining the vehicle height by driving the pump and adjusting the flow rate of the valve element, so the liquid is used as the coolant. The heat of the armature can be taken away by the liquid to effectively cool the armature, and the thermal demagnetization of the field can be prevented.

Further, the electromagnetic shock absorber has a detection unit that detects the temperature inside the outer tube, and even if the temperature detected by the detection unit exceeds the temperature threshold value, the pump is driven to circulate the liquid from the tank to the jack chamber. good. According to the electromagnetic shock absorber configured in this way, the armature can be cooled by using the jack before the temperature inside the outer tube reaches a temperature at which the field magnetism causes thermal demagnetization, so that the armature can be cooled in a timely manner. Can be cooled to prevent thermal demagnetization of the field.

Further, the jack chamber of the electromagnetic shock absorber may be annular, and the opening of the supply path to the jack chamber and the opening of the discharge path to the jack chamber may be installed on opposite sides in the circumferential direction. According to the electromagnetic shock absorber configured in this way, when the liquid is circulated to cool the armature, the low temperature liquid flowing into the jack chamber always passes around the outer tube and takes the heat of the armature. Since it is possible to secure the time from when the low temperature liquid flows into the jack chamber to when it is discharged from the tank, it is possible to efficiently cool the armature and prevent thermal demagnetization of the field.

Further, the jack chamber in the electromagnetic shock absorber may be annular, and the outer tube may have a plurality of annular grooves on the outer periphery facing the jack chamber. According to the electromagnetic shock absorber configured in this way, the surface area of the outer circumference facing the jack chamber of the outer tube is increased by providing the annular groove, and the liquid in the jack chamber efficiently removes the heat of the armature. It is possible to prevent thermal demagnetization of magnetism.

Further, a jack is attached to the outer circumference of the outer tube to form an annular jack chamber with the outer tube, and the outer circumference has a cylindrical housing provided with heat radiation fins, and the spring receiver supports the suspension spring. An electromagnetic shock absorber may be configured by having a seat portion of the above and a tubular portion provided on the inner circumference of the seat portion and in sliding contact with the housing and the outer tube. According to the electromagnetic shock absorber configured in this way, since the housing forming the jack chamber has heat radiating fins, the heat of the armature can be efficiently dissipated through the housing, and the heat of the liquid in the jack chamber can be efficiently dissipated. Since the heat dissipation efficiency of the field is also improved, the thermal demagnetization of the field can be prevented more effectively.

Then, the electromagnetic shock absorber is connected to the rod and slidably inserted into the outer tube, and is filled in the piston that divides the outer tube into the extension side chamber and the compression side chamber, and the extension side chamber and the compression side chamber. It may be provided with a passage that communicates the working liquid with the extension side chamber and the compression side chamber, and a damping valve that resists the flow of the working liquid through the passage. According to the electromagnetic shock absorber configured in this way, in addition to the force generated as a linear motor by the armature and the field, a damping force can be generated as a passive damper caused by the pressure of the working liquid, which is generated as a linear motor. In situations where the vehicle body vibration cannot be suppressed with only the possible force, it is possible to supplement with the damping force as a passive damper, and the vibration damping effect of the vehicle body can be enhanced.

According to the electromagnetic shock absorber of the present invention, it is possible to adjust the vehicle height and prevent thermal demagnetization of the field.

It is a vertical sectional view of the electromagnetic shock absorber of one Embodiment. It is an enlarged cross-sectional view of the jack part of the electromagnetic shock absorber of one Embodiment. It is a circuit diagram of the hydraulic pressure circuit in the jack of the electromagnetic shock absorber of one Embodiment. It is a block diagram of the control device which controls the electromagnetic shock absorber of one Embodiment.

Hereinafter, the present invention will be described based on the embodiments shown in the figure. As shown in FIG. 1, the electromagnetic shock absorber D in one embodiment has an outer tube 1, a tubular armature 2 fixed to the inner circumference of the outer tube 1, and an axial direction with respect to the outer tube 1. In the outer tube 1, a rod 3 having a field 4 that is movable and inserted into the armature 2, an annular spring receiver 5 provided on the outer periphery of the outer tube 1 and supporting one end of the suspension spring 6, and an outer tube 1. It is configured to have a jack chamber R on the outer periphery of the armature 2 and to include a jack J capable of moving the spring receiver 5 in the axial direction with respect to the outer tube 1 by increasing or decreasing the amount of liquid in the jack chamber R. Then, the electromagnetic shock absorber D is used by being interposed between the vehicle body and the wheels in a vehicle (not shown), and the generated thrust suppresses the vibration of the vehicle body and the wheels.

Hereinafter, each part of the electromagnetic shock absorber D will be described in detail. As shown in FIG. 1, the outer tube 1 has a cylindrical shape and is formed of a ferromagnetic material, and a plurality of annular grooves 1a along the circumferential direction are provided on the outer periphery thereof. Further, the lower end of FIG. 1 of the outer tube 1 is closed by a bottom cap 10, and the bottom cap 10 is provided with an eye 10a that enables the electromagnetic shock absorber D to be connected to a knuckle or a suspension arm that holds the wheel. There is.

Further, an annular rod guide 11 is attached to the upper end of the outer tube 1 in FIG. In this embodiment, the reservoir 12 is attached to the lower end of FIG. 1 of the outer tube 1. The reservoir 12 has a cylindrical shape and houses the free piston 13 inside. The free piston 13 is slidably inserted into the reservoir 12, divides the inside of the reservoir 12 into a liquid chamber L and an air chamber G, and communicates the liquid chamber L with the outer tube 1.

The rod 3 is inserted into the outer tube 1 so as to be movable in the axial direction, and is connected to the piston 7 which is slidably inserted into the outer tube 1. Further, a guide cylinder 8 formed of a non-magnetic material forming an annular space for accommodating the field 4 is attached to the rod 3 with the rod 3. The guide cylinder 8 includes a cylinder portion 8a and an annular cap 8b that fits into the upper end of the cylinder portion 8a in FIG. 1 to close the upper end opening of the cylinder portion 8a and fits to the outer periphery of the rod 3. .. The inner circumference of the cap 8b is attached to the outer circumference of the rod 3, the lower end of the cylinder portion 8a is attached to the rod 3 via the piston 7, and the guide cylinder 8 is attached to the rod 3. An upper spring receiver 16 is attached to the upper end of the rod 3 in FIG. 1.

The guide cylinder 8 is slidably inserted into the bush 11a provided on the inner circumference of the rod guide 11 attached to the upper end of the outer tube 1. The total length of the guide cylinder 8 is set so that even if the rod 3 penetrates into the outer tube 1 most, it protrudes upward from the rod guide 11. Therefore, the seal ring 11b, which is the inner circumference of the rod guide 11 and is mounted on the upper side of the bush 11a, is always in sliding contact with the outer circumference of the guide cylinder 8, and the inside of the outer tube 1 is kept liquidtight. There is.

A plurality of annular permanent magnets 14 are laminated and housed in the axial direction on the outer circumference of the rod 3 and the inner circumference of the guide cylinder 8. These permanent magnets 14 are laminated so that S poles and N poles appear alternately in the axial direction, and the field magnet 4 is formed by these permanent magnets 14. Since the field magnet 4 may be subjected to a magnetic field so that S poles and N poles appear alternately on the outer peripheral side of the rod 3 in the axial direction, the permanent magnets 14 may be arranged in a Halbach array. .. In that case, the axial length of the permanent magnet 14 forming the secondary magnetic pole may be shorter than that of the permanent magnet 14 forming the main magnetic pole so as to be suitable for the Halbach array.

Subsequently, the piston 7 divides the inside of the outer tube 1 into an extension side chamber R1 and a compression side chamber R2. The extension side chamber R1 and the compression side chamber R2 are filled with hydraulic oil as a hydraulic liquid. Further, the piston 7 includes a passage 7a that communicates the extension side chamber R1 and the compression side chamber R2, and a damping valve 7b provided in the passage 7a. The liquid chamber L in the reservoir 12 communicates with the compression side chamber R2, and the liquid chamber L is also filled with hydraulic oil. Although the damping valve 7b is an orifice in the drawing, it may be a choke or a leaf valve, or a damping force adjusting valve whose damping force can be adjusted.

Then, when the electromagnetic shock absorber D, in which the rod 3 moves so as to come out upward in FIG. 1 with respect to the outer tube 1, is extended, the hydraulic oil is damped from the extension side chamber R1 reduced by the piston 7 to the compression side chamber R2. It moves via 7b. Further, since the hydraulic oil for the volume in which the guide cylinder 8 exits from the outer tube 1 is insufficient in the outer tube 1, the insufficient hydraulic oil is supplied from the reservoir 12, and the free piston 13 is accompanied by this. Moves downward and expands the air chamber G by that amount. Further, when the electromagnetic shock absorber D that moves so that the rod 3 penetrates downward in FIG. 1 with respect to the outer tube 1, the hydraulic oil is attenuated from the compression side chamber R2 that is reduced by the piston 7 to the extension side chamber R1 that expands. It moves through the valve 7b. Further, since the hydraulic oil for the volume of the guide cylinder 8 entering the outer tube 1 becomes excessive in the outer tube 1, the excess hydraulic oil is absorbed in the reservoir 12, and the free piston 13 is accompanied by this. Moves upward and compresses the air chamber G.

As described above, the electromagnetic shock absorber D is a so-called single-rod type shock absorber, and the reservoir 12 performs volume compensation at the time of expansion and contraction. A cylinder may be provided to form a gap between the outer tube 1 and the outer periphery of the lower end, and this gap may be used as the reservoir 12. Further, instead of providing the reservoir 12, a free piston is slidably inserted into the outer tube 1 to provide an air chamber partitioned by the free piston below the compression side chamber R2 of the outer tube 1, and the electromagnetic shock absorber D is provided. Volume compensation may be performed during expansion and contraction.

Subsequently, the armature 2 includes a cylindrical core 20 and a winding 21 mounted on the core 20, and is mounted on the inner circumference of the outer tube 1 on the upper end side in the present embodiment. Is fixed. The core 20 includes a tubular yoke 20a fixed to the inner circumference of the outer tube 1 and a plurality of annular teeth 20b provided axially side by side on the inner circumference of the yoke 20a, and is annular between the teeth 20b. It is provided with a plurality of slots 20c formed by the recesses of the above. In the present embodiment, the winding 21 is annular and is mounted in each slot 20c, and is a U-phase, V-phase, and W-phase three-phase winding. The number of slots may be set to be suitable for the magnetic pole of the field 4, and the arrangement of the teeth 20b may be set to be suitable for the magnetic pole of the field 4 as well. Further, in the electromagnetic shock absorber D of the present embodiment, the armature 2 is attached to the inner circumference of the outer tube 1 in the range where the annular groove 1a is provided.

As described above, the electromagnetic shock absorber D can generate a force that attracts the field 4 and drives the rod 3 in the axial direction with respect to the outer tube 1 by energizing the winding 21 of the armature 2. Further, in the electromagnetic shock absorber D, when the electromagnetic shock absorber D expands and contracts, the damping valve 7b gives resistance to the flow of hydraulic oil passing through the damping valve 7b and passing through the extension side chamber R1 and the compression side chamber R2, so that a damping force due to hydraulic pressure is generated. It can also function as a passive damper. As described above, the electromagnetic shock absorber D can generate a thrust that is the sum of the force generated by the linear motor formed by the armature 2 and the field 4 and the damping force generated as the passive damper.

The jack J is attached to the outer outer circumference of the upper end of the outer tube 1 to form an annular gap between the outer circumference of the outer tube 1 and the outer circumference of the outer tube 1 and the outer circumference of the housing 30. It is provided with a jack chamber R formed by a tubular portion 5a of a spring receiver 5 in contact with the spring receiver 5. Further, as shown in FIG. 3, the jack J includes a hydraulic circuit C for supplying / discharging and circulating a liquid in the jack chamber R.

Hereinafter, the jack J will be described in detail. As shown in FIGS. 1 and 2, the housing 30 is provided on the outer periphery of the outer tube 1 with a cylindrical main body 30a arranged via the annular gap, and on the inner circumference of the lower middle end of FIG. 1 of the tubular main body 30a. An annular mounting portion 30b mounted on the outer circumference of the outer tube 1, a plurality of annular heat radiating fins 30c provided along the circumferential direction on the outer circumference of the cylindrical main body 30a, and a circumference near the lower end of the tubular main body 30a. It includes a pair of ports 30d and 30e provided on opposite sides with a phase difference of 180 degrees in the direction, and a seal ring 30f housed in an annular groove provided on the inner circumference of the upper end of the cylindrical main body 30a.

In the present embodiment, the inner circumference of the tubular main body 30a faces all the annular grooves 1a. The annular mounting portion 30b is fitted to the outer tube 1 in a state where the downward movement is restricted by the snap ring 50 mounted on the outer circumference of the outer tube 1. The outer circumference of the outer tube 1 and the inner circumference of the annular mounting portion 30b are sealed by a seal ring 1b provided on the outer circumference of the outer tube 1. A seal ring that is in close contact with the outer periphery of the outer tube 1 may be provided on the annular mounting portion 30b side, or the annular mounting portion 30b may be attached to the outer tube 1 by welding.

A spring receiver 5 is slidably fitted to the outer periphery of the upper end of the outer tube 1. The spring receiver 5 is made of a non-magnetic material such as aluminum, SUS303, or a part of austenitic stainless steel of SUS304, and has a cylindrical tubular portion 5a that is slidably fitted to the outer periphery of the outer tube 1 and a tubular portion 5a. It is configured to include a flange-shaped seat portion 5b provided on the outer periphery of the portion 5a. Further, in the electromagnetic shock absorber D of the present embodiment, the upper spring receiver 16 which is axially opposed to the spring receiver 5 is connected to the upper end of FIG. 1 of the rod 3, and the spring receiver 5 and the upper spring receiver 16 are connected. A suspension spring 6 made of a coil spring is interposed between the two. Therefore, when the rod 3 is attached to the vehicle body and the eye 10a is attached to the suspension member (not shown) connected to the wheel and the electromagnetic shock absorber D is interposed between the vehicle body and the wheel, the suspension spring 6 is compressed. Demonstrates elastic force that elastically supports the vehicle body.

The tubular portion 5a of the spring receiver 5 is in sliding contact with the inner circumference of the tubular main body 30a in the housing 30 and the outer circumference of the outer tube 1, and jacks the outer circumference of the outer tube 1 in cooperation with the housing 30 and the outer tube 1. Room R is partitioned. A seal ring 1c, which is the outer circumference of the outer tube 1 and is mounted above the annular groove 1a, is in sliding contact with the inner circumference of the spring receiver 5, and is provided on the housing 30 on the outer circumference of the spring receiver 5. The seal ring 30f is in sliding contact. Further, a seal ring 1b is arranged between the outer tube 1 and the housing 30. The jack chamber R is kept liquid-tight by these seallins 1b, 1c, and 30f.

The cylindrical main body 30a in the housing 30 is installed on the outer circumference of the outer tube 1 at the position where the armature 2 is provided, whereby the jack chamber R is the outer circumference of the outer tube 1 and the armature 2 is provided. It faces the range provided.

Then, when the liquid is supplied from the hydraulic circuit C into the jack chamber R, the liquid pushes up the tubular portion 5a of the spring receiver 5 upward in FIG. 1, so that the jack chamber R is expanded. On the contrary, when the liquid is discharged from the inside of the jack chamber R, the spring receiver 5 is pushed downward in FIG. 1 by the load received from the suspension spring 6, the tubular portion 5a invades into the housing 30, and the jack chamber R is reduced. NS. By supplying and discharging the liquid into the jack chamber R in this way, the position of the spring receiver 5 in the vertical direction can be changed, whereby the electromagnetic shock absorber D can adjust the vehicle height. It is desirable that the jack chamber R faces the outer circumference of the outer tube 1 and the range facing the armature 2 in the radial direction in a state where the tubular portion 5a is maximally penetrated into the housing 30. You may face only a part of such a range. When the armature 2 is energized, a magnetic field acts on the spring receiver 5 through the outer tube 1, but since the spring receiver 5 is a non-magnetic material, it can be smoothly displaced with respect to the outer tube 1 without being affected by the magnetic field. If the housing 30 is also made of a non-magnetic material, the magnetic flux generated by the armature 2 does not leak to the housing 30 side, so that the thrust of the electromagnetic shock absorber D can be improved.

Further, the number of heat radiating fins 30c provided on the outer periphery of the tubular main body 30a can be arbitrarily changed, and the shape of the heat radiating fins 30c can also be arbitrarily changed. The heat radiating fins 30c increase the surface area of the housing 30 to facilitate heat dissipation of the liquid in the housing 30 to the atmosphere.

As shown in FIG. 3, the hydraulic circuit C includes a discharge path 31 communicated with the port 30e of the housing 30, a tank 32 communicated with the jack chamber R via the discharge path 31, and a tank 32 for storing the liquid, and the housing 30. A supply path 33 communicating with the port 30d of the above, a pump 34 capable of sucking liquid from the tank 32 and supplying the liquid to the jack chamber R through the supply path 33, and a pump 34 provided in the supply path 33 from the jack chamber R to the pump 34. It is configured to include a check valve 35 that blocks only the flow of liquid toward it, and a valve element 36 that is provided in the discharge passage 31 and can adjust the amount of liquid in the jack chamber R.

The tank 32 is provided on the vehicle body of the vehicle, and the liquid in the flow rate required for adjusting the vehicle height is stored in the tank 32. The liquid used for the jack J may be hydraulic oil, or may be an aqueous solution obtained by adding glycols or the like to water. Further, when an aqueous solution is used, it is possible to prevent the electromagnetic shock absorber D from being rusted by using an aqueous solution to which a rust preventive agent is added.

Further, as the glycols added to water, for example, ethylene glycol and propylene glycol may be used, and by adding these ethylene glycol and propylene glycol to water, the freezing point can be lowered as compared with water alone. When an ethylene glycol aqueous solution is used as the liquid, the freezing point can be set to -15 degrees or less by setting the weight fraction of ethylene glycol in the total weight of the ethylene glycol aqueous solution to 30 wt% or more. , The vehicle height adjustment function can be maintained and demonstrated even in cold regions. When an aqueous solution of propylene glycol is used as the liquid, the freezing point can be set to -15 degrees or less by setting the weight fraction of propylene glycol to be tightened in the total weight of the aqueous solution to 30 wt% or more. , The vehicle height adjustment function can be maintained and demonstrated even in cold regions.

The discharge passage 31 is a passage that communicates the jack chamber R with the tank 32 by using the port 30e of the housing 30 as an opening to the jack chamber R. A valve element 36 is provided in the discharge path 31. The valve element 36 includes an electromagnetic on-off valve 37 provided in the discharge path 31 and a relief valve 38 provided in parallel with the electromagnetic on-off valve 37 with respect to the discharge path 31.

The electromagnetic on-off valve 37 takes a communication position when the power is turned on to communicate the jack chamber R with the tank 32, and takes a shutoff position when the power is off to cut off the communication between the jack chamber R and the tank 32. Further, the relief valve 38 opens when the jack chamber R becomes equal to or higher than a predetermined valve opening pressure, and discharges the liquid in the jack chamber R to the tank 32. The relief valve 38 plays a role of releasing the pressure in the jack chamber R so that the pressure in the jack chamber R does not become excessive and exceeds the upper limit of the pressure allowed by design.

The supply path 33 is a passage that communicates the jack chamber R with the tank 32 by using the port 30d of the housing 30 as an opening to the jack chamber R. A pump 34 is provided in the supply path 33. When the pump 34 is driven, it sucks the liquid from the tank 32 and supplies the liquid to the jack chamber R. A check valve 35 is provided between the pump 34 of the supply path 33 and the jack chamber R. The check valve 35 allows the liquid to pass from the pump 34 side to the jack chamber R, but blocks the flow of the liquid from the jack chamber R to the pump 34, so that the liquid from the jack chamber R side to the pump 34 side. Is blocking the backflow.

As shown in FIG. 4, a stroke sensor 39 is provided to detect the position of the spring receiver 5. The stroke sensor 39 may be any as long as it can detect the displacement of the spring receiver 5 with respect to the housing 30. Since the spring receiver 5 supports the lower end of the suspension spring 6, if the stroke sensor 39 detects the relative displacement between the spring receiver 5 and the housing 30 when the spring receiver 5 is raised or lowered by the jack J, the vehicle height It is possible to grasp the amount of displacement in which the height is raised or lowered.

When adjusting the vehicle height with the jack J in the present embodiment, the following may be performed. First, when it is desired to lower the vehicle height by a desired displacement amount, with the pump 34 stopped, the electromagnetic on-off valve 37 is opened to let the liquid escape to the tank 32, and the displacement of the spring receiver 5 detected by the stroke sensor 39 with respect to the housing 30. When the desired displacement amount is reached, the electromagnetic on-off valve 37 may be closed. Further, when it is desired to raise the vehicle height by a desired displacement amount, the pump 34 is driven with the electromagnetic on-off valve 37 closed to supply the liquid into the jack chamber R, and the spring receiver 5 detected by the stroke sensor 39. When the displacement with respect to the housing 30 reaches the desired displacement amount, the pump 34 may be stopped.

Further, when the liquid is circulated between the jack chamber R and the tank 32 while maintaining the vehicle height, the electromagnetic on-off valve 37 is opened while driving the pump 34. In this case, in order to match the flow rate of the liquid passing through the electromagnetic on-off valve 37 with the flow rate of the liquid discharged by the pump 34 so that the displacement detected by the stroke sensor 39 does not change, whether the electromagnetic on-off valve 37 is controlled to open or close. , The discharge flow rate of the pump 34 may be controlled, or both may be performed. When the electromagnetic on-off valve 37 is a valve capable of controlling the flow rate, the valve opening and closing of the electromagnetic on-off valve 37 may be controlled instead of opening and closing the electromagnetic on-off valve 37.

Further, the control device S controls the energization of the electromagnetic shock absorber D to the armature 2 and the control of the pump 34 and the electromagnetic on-off valve 37 of the jack J. As shown in FIG. 4, the control device S includes a current sensor 41 that detects the current flowing through the winding 21, a position sensor 42 that detects the electric angle of the field 4 with respect to the armature 2, and the stroke sensor 39 described above. A control unit 43 that controls the current flowing through the winding 21, controls the rotation speed of the pump 34, and controls the opening and closing of the electromagnetic on-off valve 37.

The control unit 43 obtains the target current applied to the winding 21 from the target thrust to be generated by the electromagnetic shock absorber D, and performs energization phase switching according to the electric angle of the field 4 with respect to the armature 2 detected by the position sensor 42. At the same time, the current flowing through each winding 21 is controlled by PWM control. Further, the control unit 43 monitors the current flowing through each winding 21 by the current sensor 41, and PI-compensates or PID-compensates the deviation between the target current and the monitored current so that the current of each winding 21 matches the target current. Control. The target thrust may be input from a control device (not shown) higher than the control device S, or the control unit 43 in the control device S may obtain the target thrust. For example, in the case of performing skyhook control, a detection means for obtaining the vertical speed of the vehicle body is provided, and the control unit 43 can obtain the target thrust by multiplying the obtained speed by the skyhook gain. Just do it. Regardless of whether the control unit 43 in the control device S obtains the target thrust or the above-mentioned higher-level control device obtains the target thrust, the control law used when obtaining the target thrust is the skyhook control law. It may be a control rule other than. Further, the target thrust is obtained as a target value of the thrust of the sum of the force generated by the electromagnetic shock absorber D as a linear motor and the damping force generated as a passive damper. Therefore, the control unit 43 may obtain the target current applied to the winding 21 by subtracting the damping force generated as the passive damper from the target thrust when the electromagnetic shock absorber D expands and contracts.

Then, when adjusting the vehicle height, the control unit 43 monitors the displacement of the spring receiver 5 detected by the stroke sensor 39, and drives the jack J until the spring receiver 5 is displaced by the displacement amount indicated by the displacement command. The spring receiver 5 is displaced. As described above, the control unit 43 drives the pump 34 to raise the spring receiver 5 in FIG. 1 without energizing the electromagnetic on-off valve 37, and closes the spring receiver 5 in FIG. To lower the pump 34, the pump 34 is stopped and the electromagnetic on-off valve 37 is energized to open the valve. Then, the control unit 43 raises or lowers the spring receiver 5, and when the displacement amount of the spring receiver 5 reaches the displacement amount indicated by the displacement command, the pump 34 is stopped, the electromagnetic on-off valve 37 is closed, and the spring receiver 5 is closed. Stop the ascent or descent of 5.

Further, the control unit 43 obtains the resistance value in each winding 21 from the current detected by the current sensor 41 and the voltage applied to each winding 21. Since the resistance value of the winding 21 changes depending on the temperature of the winding 21, the control device S can estimate the temperature of the winding 21 by obtaining the resistance value of the winding 21. Regarding the detection of the voltage applied to the winding 21, the control unit 43 may estimate from the PWM duty ratio, or a voltage sensor may be provided and detected by this voltage sensor.

Since the heat of the winding 21 raises the temperature inside the outer tube 1 and the field 4, there is a certain correlation between the temperature inside the outer tube 1 and the temperature of the field 4. Therefore, in the present embodiment, the temperature of the winding 21 is regarded as the temperature inside the outer tube 1. If the temperature of the winding 21 continues to rise, the temperature of the field 4 also continues to rise and the field 4 is thermally demagnetized. In order to prevent this, in the present embodiment, the temperature of the winding 21 When the temperature exceeds a predetermined temperature threshold, the control unit 43 drives the pump 34 while opening the electromagnetic on-off valve 37 to circulate the liquid between the jack chamber R and the tank 32. A sufficient amount of liquid is stored in the tank 32, and the liquid flowing into the tank 32 from the jack chamber R is cooled in the tank 32 and at a lower temperature than the liquid in the jack chamber R from the tank 32. Liquid is supplied into the jack chamber R. The tank 32 is preferably installed in a well-ventilated place when the vehicle is traveling in order to enhance the cooling effect of the stored liquid. Further, although the tank 32 is a container for storing the liquid, a heat radiation fin may be provided in the container to enhance the cooling effect of the liquid inside. The liquid sent from the tank 32 into the jack chamber R faces the outer peripheral surface of the portion of the outer tube 1 where the armature 2 is provided, so that the outer tube 1 is touched by the outer peripheral surface. The heat is taken from the armature 2 and returned to the tank 32. As a result, the armature 2 is cooled, so that even if the winding 21 is continuously energized, the temperature inside the outer tube 1 and the temperature of the field 4 are suppressed from rising, and the field 4 is thermally demagnetized. Is prevented.

In the present embodiment, the resistance value of the winding 21 is obtained to detect the temperature inside the outer tube 1, and the detection unit is composed of the current sensor 41 and the control unit 43 in the control device S. There is. When detecting the temperature inside the outer tube 1, a temperature sensor that directly detects the temperature inside the outer tube 1 may be used, or since it is desired to suppress the thermal demagnetization of the field 4, the temperature of the field 4 is detected by the temperature sensor. You may. Further, the temperature threshold is set lower than the temperature at which the field 4 is thermally demagnetized, and after the temperature detected by the detection unit reaches the temperature threshold, the liquid is transferred to the jack chamber R and the tank 32. Even if the armature 2 is circulated and started to be cooled, care is taken so that the cooling is not completed in time and the temperature of the field 4 does not reach the temperature at which the field magnet 4 is thermally demagnetized. Further, the temperature threshold value may be changed depending on the outside air temperature.

Further, in the present embodiment, the jack chamber R is annular, and the port 30d as an opening to the jack chamber R of the supply path 33 and the port 30e as an opening to the jack chamber R of the discharge path 31 are formed. They are installed on opposite sides in the circumferential direction. In this way, since the port 30d and the port 30e are installed on opposite sides in the circumferential direction, when the liquid is circulated for cooling the armature 2 as described above, as shown by the arrow in FIG. 2, the port The low-temperature liquid flowing into the jack chamber R from 30d always passes around the outer tube 1 to remove the heat of the armature 2, and then is returned to the tank 32 from the port 30e on the opposite side. Further, since the port 30d and the port 30e are installed on opposite sides in the circumferential direction, it is possible to secure a time for the low temperature liquid to pass around the outer tube 1 from the port 30d and reach the port 30e. , Efficiently removes heat from the armature 2 and discharges it to the tank 32.

As described above, the electromagnetic shock absorber D is movable in the axial direction with respect to the outer tube 1, the tubular armature 2 fixed to the inner circumference of the outer tube 1, and the outer tube 1 and is an armature. A rod 3 having a field 4 inserted into the outer tube 1, an annular spring receiver 5 provided on the outer periphery of the outer tube 1 to support one end of the suspension spring 6, and a jack on the outer periphery of the armature 2 in the outer tube 1. A jack J having a chamber R and capable of moving the spring receiver 5 in the axial direction with respect to the outer tube 1 by increasing or decreasing the amount of liquid in the jack chamber R is provided.

The electromagnetic shock absorber D configured in this way can not only suppress the vibration of the vehicle body by the generation of thrust, but also supply and discharge the liquid to the jack chamber R by the jack J when adjusting the vehicle height, so that the vehicle height is adjusted. It is not necessary to energize the armature 2 to maintain the height. Further, a jack chamber R is provided on the outer periphery of the outer tube 1 where the armature 2 is provided, and the spring receiver 5 and the housing 30 mounted on the outer periphery of the outer tube 1 in the jack J gain surface area like heat radiation fins. The heat of the armature 2 can be released to the atmosphere, and if the liquid in the jack chamber R is circulated, the liquid becomes a cooling liquid to take the heat of the armature 2 and cool the armature 2. From the above, the electromagnetic shock absorber D of the present embodiment can not only dissipate the heat of the armature 2 by energization to the atmosphere by using the parts of the jack J, but also utilize the liquid in the jack chamber R as a coolant. Since the armature 2 can be cooled and the armature 2 does not need to be energized when adjusting the vehicle height or maintaining the vehicle height, the vehicle height can be adjusted and the thermal demagnetization of the field 4 can be prevented. ..

As shown in FIG. 1, the jack chamber R faces in a range of half or more of the outer circumference where the armature 2 of the outer tube 1 is provided even when the spring receiver 5 is maximally penetrated into the housing 30. And when the liquid is circulated in the jack chamber R and the tank 32, the armature 2 can be cooled more efficiently. The jack chamber R is not necessarily limited to an annular shape, and may face a part of the outer tube 1 in the circumferential direction. However, it is better that the jack chamber R is an annular shape and faces the entire circumference of the outer tube 1. It is advantageous for cooling the armature 2.

Further, the jack J in the electromagnetic shock absorber D of the present embodiment has a tank 32 that is communicated with the jack chamber R via the discharge path 31 to store the liquid, and a jack chamber that sucks the liquid from the tank 32 and passes through the supply path 33. A pump 34 capable of supplying liquid to R, a check valve 35 provided in the supply path 33 to block only the flow of liquid from the jack chamber R to the pump 34, and a check valve 35 provided in the discharge path 31 in the jack chamber R. It has a valve element 36 that can adjust the amount of liquid in the above. The electromagnetic shock absorber D configured in this way can circulate the liquid between the jack chamber R and the tank 32 while maintaining the vehicle height by driving the pump 34 and adjusting the flow rate of the valve element 36, so that the liquid can be cooled. The heat of the armature 2 can be taken away by the liquid to effectively cool the armature 2, and the thermal demagnetization of the field 4 can be prevented. Further, the jack J is provided with a check valve 35, and the liquid that has entered the jack chamber R to take heat from the armature 2 and headed toward the tank 32 side flows back to the pump 34 side and is again inside the jack chamber R. Since it does not invade the armature, it does not interfere with the cooling of the armature 2.

Further, the electromagnetic shock absorber D of the present embodiment has a detection unit that detects the temperature inside the outer tube 1, and when the temperature detected by the detection unit exceeds the temperature threshold value, the pump 34 is driven to jack the tank 32. The liquid is circulated in the chamber R. According to the electromagnetic shock absorber D configured in this way, the armature 2 can be cooled by using the jack J before the temperature inside the outer tube 1 reaches a temperature at which the field 4 causes thermal demagnetization. The armature 2 can be cooled in a timely manner to prevent thermal demagnetization of the field 4.

Further, in the electromagnetic shock absorber D of the present embodiment, the jack chamber R is annular, and the port (opening) 30d to the jack chamber R of the supply path 33 and the port (opening) to the jack chamber R of the discharge path 31. Part) 30e and 30e are installed on opposite sides in the circumferential direction. According to the electromagnetic shock absorber D configured in this way, when the liquid is circulated for cooling the armature 2, the low-temperature liquid flowing into the jack chamber R always passes around the outer tube 1 and the armature 2 is used. After removing the heat from the armature, it is returned to the tank 32, and the time from when the low-temperature liquid flows into the jack chamber R to when it is discharged can be secured. Therefore, the armature 2 is efficiently cooled and the field 4 is thermally demagnetized. Can be prevented.

Further, in the electromagnetic shock absorber D of the present embodiment, the jack chamber R is annular, and the outer tube 1 has a plurality of annular grooves 1a on the outer periphery facing the jack chamber R. Therefore, according to the electromagnetic shock absorber D configured in this way, by providing the annular groove 1a, the surface area of the outer periphery of the outer tube 1 facing the jack chamber R becomes large, and the liquid in the jack chamber R increases the surface area of the armature 2. It is possible to efficiently take away the heat of the field 4 and prevent the thermal demagnetization of the field 4.

Further, in the electromagnetic shock absorber D according to the present embodiment, a jack J is mounted on the outer periphery of the outer tube 1 to form an annular jack chamber R with the outer tube 1, and a cylinder provided with heat radiation fins 30c on the outer periphery. An annular seat portion 5b having a shaped housing 30 and a spring receiver 5 supporting the suspension spring 6 and a cylindrical portion 5a provided on the inner circumference of the seat portion 5b and in sliding contact with the housing 30 and the outer tube 1. Have. According to the electromagnetic shock absorber D configured in this way, since the housing 30 forming the jack chamber R has the heat radiating fins 30c, the heat of the armature 2 can be efficiently radiated through the housing 30 and at the same time. Since the heat dissipation efficiency of the liquid in the jack chamber R is also improved, the thermal demagnetization of the field 4 can be prevented more effectively.

The electromagnetic shock absorber D of the present embodiment is connected to the rod 3 and slidably inserted into the outer tube 1, and the piston 7 divides the inside of the outer tube 1 into the extension side chamber R1 and the compression side chamber R2. The hydraulic oil (working liquid) filled in the extension side chamber R1 and the compression side chamber R2, the passage 7a communicating the extension side chamber R1 and the compression side chamber R2, and the flow of the working liquid passing through the passage 7a are given resistance. It is provided with a damping valve 7b. The electromagnetic shock absorber D configured in this way can generate a damping force as a passive damper caused by the pressure of the working liquid in addition to the force generated as a linear motor by the armature 2 and the field 4. Therefore, the electromagnetic shock absorber D of the present embodiment can be supplemented with the damping force as a passive damper in a situation where the vehicle body vibration cannot be suppressed only by the force that can be generated as a linear motor, and the vibration damping force of the vehicle body can be suppressed. The effect can be enhanced. In the present embodiment, the electromagnetic shock absorber D can function as a passive damper by filling the outer tube 1 with the working liquid and providing the piston 7 and the damping valve 7b, and can enjoy the above-mentioned advantages, but operates. It may be configured as a linear motor without liquid, piston 7, passage 7a and damping valve 7b.

Although the preferred embodiments of the present invention have been described in detail above, they can be modified, modified, and modified as long as they do not deviate from the claims.

1 ... outer tube, 1a ... annular groove, 2 ... armature, 3 ... rod, 4 ... field magnet, 5 ... spring receiver, 5a ... cylinder, 5b ... .. Seat part, 6 ... Suspension spring, 7 ... Piston, 7a ... Passage, 7b ... Damping valve, 30 ... Housing, 30c ... Radiation fin, 30d ... Port ( Supply path opening), 30e ... Port (discharge path opening), 31 ... Discharge path, 32 ... Tank, 33 ... Supply path, 34 ... Pump, 35 ... Check valve, 36 ... valve element, D ... electromagnetic shock absorber, J ... jack, R ... jack chamber, R1 ... extension side chamber, R2 ... compression side chamber

Claims (7)

Outer tube and
A cylindrical armature fixed to the inner circumference of the outer tube,
A rod that is axially movable with respect to the outer tube and has a field that is inserted into the armature.
An annular spring receiver provided on the outer circumference of the outer tube and supporting one end of the suspension spring,
A jack chamber is provided on the outer periphery of the armature in the outer tube, and the spring receiver can be moved in the axial direction with respect to the outer tube by increasing or decreasing the amount of liquid in the jack chamber. Electromagnetic shock absorber. The jack
A tank that communicates with the jack chamber via a discharge path and stores liquid,
A pump capable of sucking the liquid from the tank and supplying the liquid to the jack chamber through a supply path.
A check valve provided in the supply path to block only the flow of the liquid from the jack chamber to the pump.
The electromagnetic shock absorber according to claim 1, further comprising a valve element provided in the discharge passage and capable of adjusting the amount of liquid in the jack chamber. It has a detector that detects the temperature inside the outer tube.
The electromagnetic shock absorber according to claim 2, wherein when the temperature detected by the detection unit exceeds the temperature threshold value, the pump is driven to circulate the liquid from the tank to the jack chamber. The jack chamber is annular and
The electromagnetic wave according to claim 2 or 3, wherein the opening of the supply path to the jack chamber and the opening of the discharge path to the jack chamber are installed on opposite sides in the circumferential direction. Shock absorber. The jack chamber is annular and
The electromagnetic shock absorber according to any one of claims 1 to 4, wherein the outer tube has a plurality of annular grooves on the outer periphery facing the jack chamber. The jack
It has a tubular housing that is mounted on the outer circumference of the outer tube to form an annular jack chamber with the outer tube and has heat radiation fins on the outer circumference.
The spring receiver has an annular seat portion that supports the suspension spring, and a tubular portion that is provided on the inner circumference of the seat portion and is in sliding contact with the housing and the outer tube. The electromagnetic shock absorber according to any one of 5 to 5. A piston that is connected to the rod and slidably inserted into the outer tube and divides the outer tube into an extension side chamber and a compression side chamber.
The working liquid filled in the extension side chamber and the compression side chamber,
A passage communicating the extension side chamber and the compression side chamber,
The electromagnetic shock absorber according to any one of claims 1 to 6, further comprising a damping valve that provides resistance to the flow of the working liquid passing through the passage.

Images