JP2015105005A - Vehicle height adjustment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a newly configured vehicle height adjustment device that can preferably detect a pressure condition therein and reflect the detection result to a vehicle height control.SOLUTION: A vehicle height adjustment device 10 comprises: a plurality of air springs 12 and vehicle height adjustment valves 14 (vehicle height adjustment portions) that are provided corresponding to respective wheels of a vehicle body and adjust a vehicle height according to feeding/draining of working fluid; a pressure tank 26 that stores the working fluid; a compressor 36 that pressure-feeds the working fluid; a plurality of open/close valves (a first open/close valve 24a, a second open/close valve 24b, a third open/close valve 24c and a fourth open/close valve 24d) to be interposed between the air springs 12 sides and the pressure tank 26; a first pressure detecting portion 32a provided on an upstream side of the plurality of open/close valves; a second pressure detecting part 32b provided on a downstream side of the plurality of open/close valves; and an ECU 56 (a control portion) that controls the compressor 36 on the basis of the detection results by the first pressure detecting portion 32a and the second pressure detecting portion 32b.

Description

  Embodiments described herein relate generally to a vehicle height adjusting device.

  Conventionally, there is a vehicle having a suspension provided with an air spring or the like using compressed air. There is also a vehicle equipped with a vehicle height adjusting device using an air spring. Some vehicle height adjusting devices are called closed types. This type raises the vehicle height by supplying high-pressure air stored in a pressure tank to an air spring that changes the suspension state of each wheel. Further, the vehicle height is lowered by discharging high-pressure air from the air spring and returning it to the pressure tank.

US Patent Application Publication No. 2011/0316248

  By the way, the number of executions of the vehicle height adjustment control tends to increase with the recent high performance and high performance of vehicles. At the same time, there is a demand to increase the vehicle height adjustment speed, and there is a demand to frequently detect the pressure state on the pressure tank side and the pressure state on the air spring side and reflect them in the control.

  The present invention has been made in view of the above, and an object of the present invention is to provide a vehicle height adjustment device having a novel configuration that can detect the pressure state in the device well and reflect the result in vehicle height control. One.

  The vehicle height adjusting device according to the embodiment includes a plurality of vehicle height adjusting units that are provided corresponding to the wheels of the vehicle body and adjust the vehicle height according to supply and discharge of the working fluid, and a pressure tank that stores the working fluid. A compressor for pumping the working fluid, a plurality of on-off valves interposed between the vehicle height adjusting unit side and the pressure tank, and a first pressure detecting unit provided on the upstream side of the plurality of on-off valves A second pressure detector provided downstream of the plurality of on-off valves, and a controller that controls the compressor based on detection results of the first pressure detector and the second pressure detector. . According to this aspect, the upstream and downstream pressure states of at least the plurality of on-off valves can be detected, so that the pressure state in the apparatus can be easily managed and the vehicle height adjustment control can be executed smoothly.

  In the vehicle height adjusting device according to the embodiment, the first pressure detecting unit detects the pressure of the working fluid on the pressure tank side, and the second pressure detecting unit detects the pressure of the working fluid on the vehicle height adjusting unit side. You may make it detect. According to this aspect, it is possible to individually detect the pressure state of the working fluid on the pressure tank side and the pressure state of the working fluid on the vehicle height adjustment unit side. Further, the pressure of the working fluid on the pressure tank side and the pressure on the vehicle height adjusting unit side can be detected at the same time, and the control on the pressure tank side and the vehicle height adjusting unit side can be appropriately performed.

  In addition, the control unit of the vehicle height adjusting device according to the embodiment is configured so that the upstream side and the downstream side of the plurality of on-off valves are based on the detection result of the first pressure detection unit and the detection result of the second pressure detection unit. The pressure difference may be acquired to control the compressor. According to this aspect, when the pressure difference between the upstream side and the downstream side of the on-off valve becomes small, that is, it becomes difficult to move the working fluid due to the pressure difference between the pressure tank side and the vehicle height adjustment unit side. In this case, the compressor can be driven quickly to assist the flow of the working fluid. In addition, when the working fluid can be sufficiently moved due to the pressure difference between the pressure tank side and the vehicle height adjustment side, the assist of the working fluid flow by the compressor can be interrupted, so that the compressor is appropriately driven and controlled. Thus, it can contribute to power saving and suppression of driving noise and vibration.

  Further, the first pressure detection unit and the second pressure detection unit of the vehicle height adjusting device according to the embodiment may be included in a valve body block formed by the plurality of on-off valves. According to this aspect, the integration of the pressure detector and the valve body block can contribute to a reduction in the number of parts and an improvement in assembly efficiency.

  In the vehicle height adjustment device according to the embodiment, the first pressure detection unit is disposed corresponding to the pressure tank, and the second pressure detection unit corresponds to any one of the plurality of vehicle height adjustment units. May be arranged. According to this aspect, the first pressure detection unit and the second pressure detection unit can be individually arranged, and the degree of freedom in arrangement is improved. Further, for example, it can be arranged in a vehicle interior or the like that is not easily affected by the surrounding environment or external force application, and the pressure detection unit can be easily protected.

  Further, the plurality of on-off valves of the vehicle height adjusting device according to the embodiment include a first on-off valve and a second on-off valve, one end of which is connected to the pressure tank, and one end of the on-off valve and the second on-off valve of the compressor. A third on-off valve connected to the other end side of the valve and the other end side connected to the vehicle height adjusting unit side, and one end side connected to the inflow side of the compressor and the other end side of the first on-off valve And the other end side includes a fourth on-off valve connected to the vehicle height adjusting unit side, and the control unit causes the working fluid to flow from the pressure tank to the vehicle height adjusting unit due to a pressure difference between the two, At least one of a first flow path system formed by opening the first open / close valve and the fourth open / close valve, and a second flow path system formed by opening the second open / close valve and the third open / close valve. May be selected. According to this aspect, the first flow path system and the case where the first flow path system or the second flow path system is selected while the vehicle height adjustment control is performed smoothly while the pressure state in the apparatus is well managed When both of the second flow path systems are selected, it is possible to switch the ease of flow of the working fluid per unit time (the amount of flow of the working fluid). This can be realized by switching the open / close state.

  Further, the plurality of on-off valves of the vehicle height adjusting device according to the embodiment include a first on-off valve and a second on-off valve, one end of which is connected to the pressure tank, and one end of the on-off valve and the second on-off valve of the compressor. A third on-off valve connected to the other end side of the valve and the other end side connected to the vehicle height adjusting unit side, and one end side connected to the inflow side of the compressor and the other end side of the first on-off valve And the other end side includes a fourth on-off valve connected to the vehicle height adjusting unit side, and the control unit causes the working fluid to flow from the pressure tank to the vehicle height adjusting unit due to a pressure difference between the two, The first flow path system formed by opening the first open / close valve and the fourth open / close valve, and the second flow path system formed by opening the second open / close valve and the third open / close valve are used. It may be. According to this aspect, by using both the first flow path system and the second flow path system while managing the pressure state in the apparatus well and performing the vehicle height adjustment control smoothly, The height of the working fluid can be improved (the flow amount of the working fluid), and the vehicle height can be rapidly controlled.

  In addition, a fluid regenerator and a throttle mechanism are disposed on the compressor outflow side of the vehicle height adjusting apparatus according to the embodiment, and the other end side of the second on-off valve and one end side of the third on-off valve are mutually connected. In addition to being connected, the diaphragm mechanism may be connected. According to this aspect, while managing the pressure state in the apparatus satisfactorily and performing the vehicle height adjustment control smoothly, even if the fluid regenerating apparatus for maintaining the quality of the working fluid is disposed in the flow path, When the working fluid moves from the pressure tank to the vehicle height adjustment unit due to the differential pressure, the working fluid can flow from the second on-off valve to the third on-off valve, and the fluid on the outflow side of the compressor that causes one of the pressure losses. The reproduction device and the diaphragm mechanism can be prevented from passing. As a result, it is possible to contribute to suppressing a decrease in the vehicle height adjustment speed.

FIG. 1 is a diagram illustrating a configuration of a vehicle height adjusting device according to an embodiment, and is a diagram illustrating a state where there is no flow of working fluid. FIG. 2 is a diagram illustrating the state of the on-off valve and the flow of the working fluid when the vehicle height increase control is executed in a vehicle non-driving state in the vehicle height adjusting device according to the embodiment. FIG. 3 is a diagram for explaining the state of the on-off valve and the flow of the working fluid when the vehicle height increase control is executed in a driving state in the vehicle height adjusting device according to the embodiment. FIG. 4 is a diagram illustrating the state of the on-off valve and the flow of the working fluid when the vehicle height lowering control is executed with the compressor being driven in the vehicle height adjusting device according to the embodiment. FIG. 5 is a flowchart illustrating vehicle height adjustment control of the vehicle height adjustment device according to the embodiment. FIG. 6 is a diagram illustrating another arrangement example of the first pressure sensor and the second pressure sensor of the vehicle height adjusting device according to the embodiment.

  Hereinafter, exemplary embodiments of the present invention are disclosed. The configuration of the embodiment shown below, and the operation and result (effect) brought about by the configuration are merely examples. The present invention can be realized by configurations other than those disclosed in the following embodiments, and various effects (including derivative effects) obtained by the basic configuration can be obtained.

  FIG. 1 is a diagram illustrating a configuration of a vehicle height adjusting device 10 according to the embodiment, and is a diagram illustrating a state where there is no flow of working fluid.

  Air wheels 12FR, 12FL, 12RR, and 12RL that function as vehicle height adjustment units are respectively provided on the wheels of the vehicle that are not shown in the drawings (hereinafter, the air springs 12 may be simply referred to as “air springs 12” if they are not distinguished from each other). ) Is connected. Each air spring 12 changes the suspension state of the wheel with respect to the vehicle body of the vehicle according to supply and discharge of the working fluid (for example, air). Further, it has a function of absorbing the vibration of the vehicle by the elasticity of the compressed air sealed in the air spring 12. The air springs 12FR and 12FL may be referred to as front wheel height adjustment units. In addition, the air springs 12RR and 12RL may be referred to as rear wheel height adjustment units. A known structure can be used for the air spring 12. Since the air spring 12 uses the elasticity of air, it is easier to absorb fine vibration than the metal spring. Further, by controlling the air pressure, the vehicle height can be kept constant, adjusted to a desired vehicle height, or the spring constant can be changed to a desired value.

  Air springs 12FR and 12FL which are front wheel vehicle height adjusting portions are connected to a main flow path 16 through which a working fluid flows via vehicle height adjusting valves 14FR and 14FL. Similarly, the air springs 12RR and 12RL, which are rear wheel vehicle height adjusting portions, are connected to the main flow path 16 through which the working fluid flows via the vehicle height adjusting valves 14RR and 14RL. When the vehicle height adjustment valves 14FR, 14FL, 14RR, and 14RL are not distinguished from each other, they may be simply indicated as “vehicle height adjustment valve 14”. In the present embodiment, the air spring 12 and the vehicle height adjustment valve 14 may be collectively referred to as a vehicle height adjustment unit.

  In the present embodiment, the vehicle height adjustment valves 14FR and 14FL are embedded and disposed in a flow path block formed of, for example, metal or resin to constitute the front wheel valve unit 18a. Similarly, the vehicle height adjusting valves 14RR and 14RL are embedded in the flow path block to constitute the rear wheel valve unit 18b. In another embodiment, each vehicle height adjustment valve 14 may be arranged individually. In this case, the layout freedom of each vehicle height adjusting valve 14 is improved. Further, the four vehicle height adjustment valves 14 may be integrated into a unit. In this case, it can contribute to the reduction of the number of parts by unitization.

  As shown in FIG. 1, by configuring the front wheel valve unit 18a and the rear wheel valve unit 18b as separate units, the front wheel valve unit 18a can be disposed on the front wheel side. As a result, the length of the flow path piping from the front wheel valve unit 18a to each air spring 12 on the front wheel side can be shortened as compared with the case where all the vehicle height adjustment valves 14 are unitized. Similarly, the rear wheel valve unit 18b can be arranged on the rear wheel side, and the length of the flow path pipe from the rear wheel valve unit 18b to each air spring 12 on the rear wheel side is summarized for all the vehicle height adjustment valves 14. Can be shortened compared to the case of unitization. As a result, the routing of the flow path piping is facilitated and the length of the flow path piping is shortened, thereby reducing the risk of damage to the flow path piping.

  A first port 18a1 to which the main flow path 16 is connected is formed on one end surface of the front wheel valve unit 18a. Inside the front wheel valve unit 18a, the first port 18a1 is one end and the other end is the second port 18a2. The main flow channel 20 is formed through. In the front wheel valve unit 18a, two main flow channel channels 20 and two sub flow channel channels 22 are branched. One end of the vehicle height adjusting valve 14FR is connected to one of the sub-flow channel 22 and the other end of the vehicle height adjusting valve 14FR is connected to the air spring 12FR via the third port 18a3. Similarly, one end of the vehicle height adjusting valve 14FL is connected to the other one of the sub-flow channel 22 and the other end of the vehicle height adjusting valve 14FL is connected to the air spring 12FL via the fourth port 18a4. .

  A communication main channel 16a (main channel 16) is connected to the second port 18a2. The communication main flow path 16a is connected to the first port 18b1 of the rear wheel valve unit 18b. A main flow channel 20 having a first port 18b1 as one end is formed inside the rear wheel valve unit 18b. In the rear wheel valve unit 18b, two main flow channel 20 to sub flow channel 22 are also branched. One end of the vehicle height adjusting valve 14RR is connected to one of the sub-flow channel 22 and the other end of the vehicle height adjusting valve 14RR is connected to the air spring 12RR via the second port 18b2. One end of the vehicle height adjusting valve 14RL is connected to the other one of the sub-channel channels 22, and the other end of the vehicle height adjusting valve 14RL is connected to the air spring 12RL via the third port 18b3.

  In the case of FIG. 1, the front wheel valve unit 18a uses a 4-port type and the rear wheel valve unit 18b uses a 3-port type. For example, the same 4-port is used on the front wheel side and the rear wheel side. It is also possible to use a type of valve unit. When the same 4-port type as the front wheel valve unit 18a is used as the rear wheel valve unit 18b, the port corresponding to the second port 18a1 is sealed with a plug cap (mekula plug). In this case, it is possible to contribute to a reduction in the types of parts and a reduction in design cost by sharing the valve unit.

  Each of the vehicle height adjustment valves 14 (14FR, 14FL, 14RR, 14RL) can use the same type of on-off valve, and has, for example, a solenoid and a spring that are ON / OFF controlled. Any of the control valves can be a normally closed electromagnetic control valve that is closed when the solenoid is not energized.

  The main flow path 16 is connected to the pressure tank 26 via the circuit valve block 24 and the tank connection main flow path 16b. The circuit valve block 24 is connected to the outflow side of the compressor unit 30 via the compressor outflow passage 28a. The circuit valve block 24 is connected to the inflow side of the compressor unit 30 through the compressor inflow passage 28b. The circuit valve block 24 is configured as a valve body block including a plurality of on-off valves, for example, four on-off valves. Specifically, the circuit valve block 24 includes a first on-off valve 24a, a second on-off valve 24b, a third on-off valve 24c, and a fourth on-off valve 24d. One end side of the first on-off valve 24a and the second on-off valve 24b is connected to the pressure tank 26 via the tank connection main channel 16b (main channel 16). One end side of the third on-off valve 24c is connected to the outflow side of the compressor unit 30 via the compressor outflow passage 28a, and is connected to the other end side of the second on-off valve 24b. Further, the other end side of the third on-off valve 24c is connected to the air spring 12 side (vehicle height adjusting unit side, front wheel valve unit 18a side). The fourth on-off valve 24d is connected at one end to the inflow side of the compressor unit 30 via the compressor inflow passage 28b and to the other end of the first on-off valve 24a. The other end side of the fourth on-off valve 24d is connected to the air spring 12 side (vehicle height adjusting unit side, front wheel valve unit 18a side).

  For the first on-off valve 24a, the second on-off valve 24b, the third on-off valve 24c, and the fourth on-off valve 24d included in the circuit valve block 24, the same type of on-off valve can be used. For example, ON / OFF control is performed. It has a solenoid and a spring. Any of the on-off valves can be a normally closed electromagnetic control valve that is closed when the solenoid is in a non-energized state.

  The vehicle height adjusting device 10 of the present embodiment includes a first pressure sensor 32a and a second pressure sensor 32b. In the case of FIG. 1, for example, the first pressure sensor 32a is disposed upstream of the circuit valve block 24 (the plurality of on-off valves), and the second pressure sensor 32b is disposed downstream. That is, the circuit valve block 24 (valve block) detects the pressure on the first pressure sensor 32a that detects the pressure on the pressure tank 26 side and the pressure on the air spring 12 side (vehicle height adjustment unit side, front wheel valve unit 18a side). A second pressure sensor 32b is included. The circuit valve block 24 is formed of, for example, metal or resin, and has a channel for connecting the first on-off valve 24a, the second on-off valve 24b, the third on-off valve 24c, and the fourth on-off valve 24d as described above. Is formed. The first pressure sensor 32a is connected to a channel for connecting one end of the first on-off valve 24a or one end of the second on-off valve 24b to the tank connection main flow path 16b (main flow path 16) (in the case of FIG. 1). , Connected to a channel extending from one end of the first on-off valve 24a). The second pressure sensor 32b is connected to a channel for connecting one end of the third on-off valve 24c or one end of the fourth on-off valve 24d to the main flow path 16 (in the case of FIG. 1, the third on-off valve 24c is connected to a channel extending from one end of 24c).

  For example, when the first on-off valve 24a and the second on-off valve 24b are closed, the first pressure sensor 32a can accurately detect the static pressure on the pressure tank 26 side. Further, when at least one of the first on-off valve 24a and the second on-off valve 24b is opened and the working fluid is flowing, the dynamic pressure on the pressure tank 26 side can be detected. Similarly, the second pressure sensor 32b closes the third on-off valve 24c and the fourth on-off valve 24d, and at least opens the vehicle height adjustment valve 14FR or the vehicle height adjustment valve 14FL on the front wheel side. The static pressure on the air spring 12 side can be measured. The second pressure sensor 32b closes the third on-off valve 24c and the fourth on-off valve 24d, closes the vehicle height adjusting valve 14RR and the vehicle height adjusting valve 14RL, and sets the vehicle height adjusting valve. One of 14FR or the vehicle height adjusting valve 14FL is opened. As a result, the static pressure of either the air spring 12FR or the air spring 12FL on the front wheel side can be detected. Moreover, the average static pressure of both the air springs 12FR and 12FL can be detected by opening both the vehicle height adjusting valve 14FR and the vehicle height adjusting valve 14FL. The second pressure sensor 32b closes the third on-off valve 24c and the fourth on-off valve 24d, closes the vehicle height adjusting valve 14FR and the vehicle height adjusting valve 14FL, and closes the vehicle height adjusting valve. One of 14RR or the vehicle height adjusting valve 14RL is opened. As a result, the static pressure of either the air spring 12RR or the air spring 12RL on the rear wheel side can be detected. Moreover, the average static pressure of both air springs 12RR and 12RL can be detected by opening both the vehicle height adjusting valve 14RR and the vehicle height adjusting valve 14RL. Further, the second pressure sensor 32b closes the third on-off valve 24c and the fourth on-off valve 24d, and adjusts the vehicle height adjusting valve 14FR, the vehicle height adjusting valve 14FL, the vehicle height adjusting valve 14RR, and the vehicle height adjusting valve. 14RL is opened. As a result, the static pressure as a whole of the air springs 12FR, 12FL, 12RR, 12RL corresponding to all the wheels can be detected. Further, the second pressure sensor 32b is connected to the air spring 12 side (the vehicle height adjustment unit side, the front wheel valve unit 18a and the rear wheel valve unit 18b side) when the third on-off valve 24c and the fourth on-off valve 24d are in the open state. The dynamic pressure can be measured.

  As described above, the first pressure sensor 32a can detect the pressure (static pressure or dynamic pressure) on the upstream side (for example, the pressure tank 26 side) of the circuit valve block 24, and the second pressure sensor 32b can detect the circuit. The pressure (static pressure or dynamic pressure) on the downstream side of the valve block 24 (for example, the air spring 12 side) can be detected. As will be described later, the vehicle height can be adjusted by causing the working fluid to flow from the pressure tank 26 side to the air spring 12 side by the pressure difference (differential pressure) between the pressure on the pressure tank 26 side and the pressure on the air spring 12 side. In other words, when the pressure difference is small, the working fluid for adjusting the vehicle height cannot be sufficiently flowed, so that the compressor unit 30 needs to be driven. Therefore, the vehicle height adjusting device 10 acquires (calculates) a pressure difference (differential pressure) based on the detection results of the first pressure sensor 32a and the second pressure sensor 32b, and drives the compressor unit 30 using the result. Control can be performed. For example, in the vehicle height increase control, when the pressure difference between the pressure tank 26 side and the air spring 12 side is equal to or greater than a predetermined value (threshold value), the working fluid can be caused to flow toward the air spring 12 by the pressure difference. In this case, the compressor 36 can be non-driven. On the other hand, when the vehicle height increase control is continued when the pressure difference between the pressure tank 26 side and the air spring 12 side is less than a predetermined value (threshold value), the timing (the timing when the compressor 36 needs to feed pressure). Thus, the compressor 36 can be driven.

  The pressure tank 26 is made of, for example, metal or resin, and has pressure resistance and capacity that can sufficiently withstand the pressure generated in the flow path system including when the vehicle height adjustment is controlled by the air spring 12 and when it is not controlled. Yes. Further, the pressure tank 26 has a relief valve 26b for reducing the pressure when the internal pressure of the tank body 26a exceeds a set pressure (a pressure set in advance by a test or the like) for some reason.

  The compressor unit 30 mainly includes a throttle mechanism 40 including a compressor 36 driven by a motor 34, a dryer 38, an orifice 40a, and a check valve 40b. In the case of FIG. 1, an example including a relief valve 42, check valves 44, 46, 48, filters 50, 52, etc. is shown.

  The compressor unit 30 is configured such that when the pressure difference between the pressure tank 26 side and the air spring 12 side becomes equal to or smaller than a predetermined value (a value set in advance by a test or the like) during vehicle height increase control, or during the vehicle height decrease control. When pumping (returning) the working fluid from the side to the pressure tank 26, the compressor 34 is operated by the motor 34 to pump the working fluid. Note that the vehicle height adjusting device 10 of the present embodiment is a closed vehicle that adjusts the vehicle height by moving the working fluid in the path (air sealed from the beginning) between the pressure tank 26 side and the air spring 12 side. Type of device. Therefore, basically, outside air does not enter the apparatus and it can be considered that there is no environmental change such as humidity fluctuation. Therefore, in the case of a closed type apparatus, basically, the dryer 38 and the diaphragm mechanism 40 can be omitted. However, the working fluid (air) in the apparatus may leak to the outside for some reason. In such a case, the atmosphere (outside air) is taken in from the outside via the filter 52 and the check valve 48, and the working fluid in the apparatus is replenished. In this case, the atmosphere (outside air) may contain moisture (humidity) that is disadvantageous to the components in the vehicle height adjusting device 10. Therefore, the vehicle height adjusting device 10 shown in FIG. 1 is provided with a throttle 38 for adjusting the passage speed of the atmosphere in the dryer 38 that removes a predetermined amount of moisture in the taken-in atmosphere on the downstream side of the compressor 36. It has been. The compressor unit 30 has a relief valve 42 in order to reduce the pressure when the pressure in the vehicle height adjusting device 10 exceeds the limit pressure for some reason. The relief valve 42 includes, for example, a solenoid that is ON / OFF controlled and a spring, and can be a normally closed electromagnetic control valve that is closed when the solenoid is in a non-energized state. In addition, the relief valve 42 of this embodiment does not maintain the closed state at the time of deenergization in any case, and the pressure in the vehicle height adjusting device 10 exceeds the limit pressure (the pressure set in advance by a test or the like). A check valve 54 that allows the working fluid to flow in the direction of opening to the atmosphere. For example, when some trouble occurs and the internal pressure of the vehicle height adjusting device 10 exceeds the limit pressure, the valve is opened against the urging force of the check valve 54, and the pressure is reduced so that it automatically falls below the limit pressure. Done. The relief valve 42 can also shift to a valve open state based on a control signal from a control unit described later, and can reduce the internal pressure of the vehicle height adjusting device 10 regardless of the limit pressure.

  The vehicle height adjusting device 10 configured as described above is controlled by a control unit (ECU) 56 included in the vehicle height adjusting device 10 such as a vehicle height adjusting unit (such as an air spring or a vehicle height adjusting valve described later). Control related to adjustment is executed. For example, the ECU 56 detects a vehicle height adjustment request acquired via a controller area network (CAN) or a detection result of the vehicle height sensor 58 that detects the expansion / contraction (vehicle height) state of each air spring 12. The detection results of the first pressure sensor 32a and the second pressure sensor 32b can be acquired. Based on the acquired information, the ECU 56 adjusts the vehicle height adjustment valves 14FR, 14FL, 14RR, 14RL, the first on-off valve 24a, the second on-off valve 24b, the third on-off valve 24c, the fourth on-off valve 24d, and the relief valve. Open / close control of 42 and the like and drive control of the motor 34 are performed. In addition, in the case of FIG. 1, although the single ECU56 has shown the example which controls each control object integratedly, the control part which controls each control object separately, and the control which groups and controls several control objects May be provided, and a higher-level control unit may be provided to control the integrated control.

  As described above, in the vehicle height adjusting device 10 of the present embodiment, the first pressure sensor 32a is disposed on the upstream side of the circuit valve block 24, and the second pressure sensor 32b is disposed on the downstream side, whereby the pressure tank 26 is disposed. Side and air spring 12 side pressure states can be detected. In particular, the pressure state during vehicle height increase control can be detected in real time. As a result, the ECU 56 accurately determines whether or not the working fluid can flow due to the pressure difference. If the pressure difference is insufficient, the ECU 36 can drive the compressor 36 only at a necessary period at an appropriate timing. As a result, the drive control of the compressor 36 is optimized, which can contribute to power saving control and reduction of noise and vibration caused by the drive of the compressor 36. By using the first pressure sensor 32a and the second pressure sensor 32b, the pressure state on the pressure tank 26 side and the pressure state on the air spring 12 side can be detected in real time and reflected in the vehicle height control. For example, smooth vehicle height adjustment can be realized at all times by driving the compressor 36 at an appropriate timing as described above. In addition, smooth vehicle height adjustment according to the road surface condition can be realized. As a result, it can contribute to an improvement in ride comfort and operability.

  Further, since the compressor 36 can be operated at an appropriate timing, the vehicle body is maintained in a substantially horizontal state by an appropriate vehicle height adjustment even when the vehicle body is tilted to the left or right, for example, when a wheel rides on a curb or the like. It is possible to reduce the sense of discomfort and anxiety of the passengers. Moreover, it becomes possible to maintain the force applied to the door (the force applied to the hinge portion) in the same manner as when the vehicle body is in a horizontal state, and the door can be opened and closed easily. Moreover, boarding / exiting can be made the same as in the horizontal state.

  The control of the vehicle height adjustment device 10 configured as described above when the vehicle height is raised and when the vehicle height is lowered will be described in detail with reference to FIGS.

  First, when the vehicle height increase control is performed using FIG. 2, the pressure on the pressure tank 26 side is sufficiently higher than the pressure on the air spring 12 side, and the operation is performed by the pressure difference between the pressure tank 26 side and the air spring 12 side. The operation of the vehicle height adjusting device 10 when fluid (air) can flow from the pressure tank 26 to each air spring 12 will be described. The ECU 56 acquires the pressure on the pressure tank 26 side based on the detection result of the first pressure sensor 32a, acquires the pressure on the air spring 12 side based on the detection result of the second pressure sensor 32b, and calculates the pressure difference. Thus, it is determined whether or not the working fluid (air) can be moved due to the pressure difference.

  By the way, when performing vehicle height increase adjustment control, it is preferable to change the vehicle height adjustment speed in accordance with the situation. For example, when getting on and off the vehicle, there is a case where it is desired to raise the vehicle height in order to reduce the burden of getting on and off the passenger. In such a case, it is desirable to quickly complete the vehicle height rise so that passengers can get on and off. Further, during vehicle travel, it may be preferable to increase the vehicle height according to the travel state (speed, travel road surface condition, etc.). In this case, it is desirable to raise the vehicle height within an ascent speed range that does not cause a sense of incongruity while maintaining stable travel.

  When the vehicle height adjusting device 10 performs vehicle height increase control, the ECU 56 controls the opening / closing of the first opening / closing valve 24a, the second opening / closing valve 24b, the third opening / closing valve 24c, and the fourth opening / closing valve 24d included in the circuit valve block 24. And the vehicle height adjusting valves 14FR, 14FL, 14RR, 14RL are controlled to be opened.

  The vehicle height adjusting device 10 of the present embodiment operates by changing the combination of the open / close states of the first open / close valve 24a, the second open / close valve 24b, the third open / close valve 24c, and the fourth open / close valve 24d of the circuit valve block 24. The flow mode (flow direction, flow amount, etc.) of the fluid can be switched. For example, when the working fluid is caused to flow from the pressure tank 26 side to the vehicle height adjusting unit side (air spring 12 side) due to a pressure difference between the two, the ECU 56 opens the first on-off valve 24a and the fourth on-off valve 24d. It is possible to select to use at least one of the first flow path system formed by opening the second open / close valve 24b and the third open / close valve 24c. For example, the first flow mode of the first flow path system (flow path opening diameter, easy flow due to flow resistance) and the second flow mode of the second flow path system (flow path open diameter, easy flow due to flow resistance) ) Are substantially the same, and the ECU 56 considers either the first flow path system or the second flow path system. In this case, the working fluid that has flowed out of the pressure tank 26 via the tank connection main flow path 16b passes through the first flow path system or the second flow path system, and each air spring in a first speed mode (for example, a low speed increase mode). The air spring 12 can be extended by opening the vehicle height adjusting valves 14 and the vehicle height can be increased at a low speed.

  Further, when the ECU 56 selects both the first flow path system and the second flow path system, the ease of flow of the working fluid is substantially doubled compared to the case where either one is selected, and the first speed is increased. The working fluid of the second speed mode (for example, the high speed rising mode) faster than the mode can be supplied to each air spring 12 side. As a result, the air springs 12 are extended by opening the vehicle height adjusting valves 14, and the vehicle height can be increased at a higher speed than in the first speed mode.

  As described above, by selecting the first flow path system and the second flow path system, it becomes possible to switch the ease of flow of the working fluid per unit time (the flow amount of the working fluid), and the vehicle height increases. The speed can be easily changed. In another embodiment, the first flow mode of the first flow path system defined by the opening of the first on-off valve 24a and the fourth on-off valve 24d and the second on-off valve 24b and the third on-off valve 24c The second flow mode of the second flow path system defined by the valve opening may be different. For example, the opening diameter of the on-off valve is made different between the first flow path system and the second flow path system. As a result, when the ECU 56 opens the first on-off valve 24a and the fourth on-off valve 24d and selects the first flow path system, for example, a low-speed rise mode is set. Moreover, when ECU56 opens the 2nd on-off valve 24b and the 3rd on-off valve 24c, and selects the 2nd flow-path system, it becomes a medium speed raise aspect, for example. Furthermore, when ECU56 selects both the 1st flow path system and the 2nd flow path system, it can be set as a high-speed raise aspect.

  Further, the selection of the first flow path system and the second flow path system as described above may be performed a plurality of times during one vehicle height raising process. For example, the rising speed in the vehicle height rising initial period is the first speed mode using one of the first flow path system or the second flow path system, and both the first flow path system and the second flow path system are used in the intermediate period. The second speed mode may be faster than the first speed mode, and the first speed mode may be set again in the final period. Thus, by starting the vehicle height increase slowly in the first speed mode, it is possible to reduce the shock at the start of the increase. Also, by shifting to the high speed increase in the second speed mode in the intermediate period, the time until the vehicle height increase control is completed is shortened, and by switching to the slow vehicle height increase in the first speed mode again in the final period, Shock at the time of ascending stop can be reduced

  Incidentally, in the case of the vehicle height adjusting device 10 of the present embodiment, as shown in FIG. 2 and the like, the other end side of the second on-off valve 24b and one end side of the third on-off valve 24c are both connected to the throttle mechanism 40. The other end side of the second on-off valve 24b is also connected to one end side of the third on-off valve 24c. That is, when the working fluid flows to the air spring 12 side based on the pressure difference between the pressure tank 26 side and the air spring 12 side, the first on-off valve 24a and the throttle valve 40a, that is, regardless of the compressor unit 30, are provided. The working fluid is allowed to pass through either the first flow path system formed by the fourth on-off valve 24d or the second flow path system formed by the second on-off valve 24b and the third on-off valve 24c or both. Can do. In other words, when the working fluid is caused to flow by the pressure difference, it is not necessary to pass through the compressor unit 30. Therefore, the flow path when the working fluid is caused to flow by the pressure difference is simplified, and the occurrence of pressure loss during the flow can be reduced.

  In the case of the vehicle height adjusting device 10, basically, the working fluid is caused to flow toward the air spring 12 due to the pressure difference between the pressure on the pressure tank 26 side and the air spring 12 side. However, as a result of the working fluid flowing from the pressure tank 26 side to the air spring 12 side, there may be no pressure difference between the pressure tank 26 side and the air spring 12 side enough to cause the working fluid to flow sufficiently. Further, there may be a case where there is not a sufficient pressure difference (differential pressure) between the pressure tank 26 side and the air spring 12 side at the time of starting the vehicle height increase control. In such a case, the ECU 56 drives the motor 34 of the compressor unit 30 to forcibly pump up the working fluid from the pressure tank 26 by the compressor 36 and pump it to the air spring 12 side.

  FIG. 3 shows the operation of the vehicle height adjusting device 10 when the working fluid is pumped to the air spring 12 side using the compressor 36 during the vehicle height raising control. For example, based on the detection results of the first pressure sensor 32a and the second pressure sensor 32b, when the pressure difference between the pressure tank 26 side and the air spring 12 side becomes a predetermined value or less, the ECU 56 sets the first on-off valve 24a, the first The on / off state of the second on / off valve 24b, the third on / off valve 24c, and the fourth on / off valve 24d is switched, and the compressor 36 starts to pump the working fluid. The predetermined value of the pressure difference that triggers switching of the open / close state can be determined in advance by a test or the like. For example, a differential pressure value can be determined such that the vehicle height increase speed is lower than a predetermined value. In this case, it is desirable to start pumping by the compressor 36 before the vehicle height rise stops.

  In another embodiment, the start of pumping by the compressor 36 may be executed based on the detection result from the vehicle height sensor 58. That is, when the pressure difference between the pressure tank 26 side and the air spring 12 side decreases, the vehicle height increasing speed also decreases. Therefore, the ECU 56 time-differentiates the vehicle height values provided from the vehicle height sensors 58 to calculate the vehicle height increase speed, and the vehicle height increase speed is equal to or lower than a predetermined value (a lower limit increase speed determined in advance by a test or the like). In such a case, pumping of the working fluid by the compressor 36 may be started. Alternatively, the start of driving of the compressor 36 may be determined using both the detection results of the first pressure sensor 32a and the second pressure sensor 32b and the detection result of the vehicle height sensor 58.

  When the pressure difference based on the detection results by the first pressure sensor 32a and the second pressure sensor 32b is equal to or less than a predetermined value, or the vehicle height increasing speed based on the vehicle height value detected by each vehicle height sensor 58 is determined by the ECU 56. In the following case, as shown in FIG. 3, the first on-off valve 24a is opened, and the fourth on-off valve 24d is closed. In this state, the pressure tank 26 side and the compressor 36 side are in communication. Further, the second on-off valve 24b is closed, and the third on-off valve 24c is opened. In this manner, the compressor 36 side and the air spring 12 side are in communication. As a result, when the compressor 36 is driven, the working fluid in the pressure tank 26 is pumped up to the compressor 36 via the tank connection main channel 16b, the first on-off valve 24a, and the compressor inflow channel 28b. The pumped working fluid is compressed and pumped to the air spring 12 side through the compressor outflow passage 28a and the third on-off valve 24c. As a result, the vehicle height increase control of each air spring 12 can be executed even when there is no sufficient pressure difference between the pressure tank 26 side and the air spring 12 side. In this case, the vehicle height increasing speed is determined by the output of the compressor 36, that is, the output of the motor 34. Therefore, the ECU 56 controls the output of the motor 34 in accordance with a required vehicle height increase speed, for example, a high speed vehicle height increase request or a low speed vehicle height increase request. In addition, as described above, the ECU 56 may control the output of the motor 34 also when the vehicle height increase speed is changed a plurality of times during one vehicle height increase process.

  Even when there is a pressure difference between the pressure tank 26 side and the air spring 12 side before the vehicle height raising control or during the vehicle height raising control, the vehicle weight increases, for example, when the number of passengers increases or the load increases. Since the load to be supported by the air spring 12 increases, the air spring 12 is shortened. As a result, the pressure on the air spring 12 side may increase, and there may be no pressure difference (differential pressure) between the pressure tank 26 side. Even in such a case, the vehicle height increase speed decreases. The situation can be detected based on the detection values of the first pressure sensor 32 a and the second pressure sensor 32 b or the vehicle height sensor 58. Therefore, the ECU 56 can start pumping by the compressor 36 at an appropriate timing.

  Next, the operation of the vehicle height adjusting device 10 during vehicle height lowering control will be described with reference to FIG. For example, when acquiring the vehicle height lowering request acquired via CAN, the ECU 56 switches the opening / closing states of the first opening / closing valve 24a, the second opening / closing valve 24b, the third opening / closing valve 24c, and the fourth opening / closing valve 24d. As a result, the working fluid can be pumped from the air spring 12 side by the compressor 36 and returned to the pressure tank 26 (the working fluid is pumped toward the pressure tank 26), and the air spring 12 is shortened to increase the vehicle height. Can be lowered.

  When executing the vehicle height lowering control, the ECU 56 closes the first on-off valve 24a and opens the fourth on-off valve 24d as shown in FIG. Further, the second on-off valve 24b is opened, and the third on-off valve 24c is kept closed. Further, the vehicle height adjusting valves 14FR, 14FL, 14RR, and 14RL are opened. As a result, the air spring 12 side and the compressor 36 are in communication with each other via the fourth on-off valve 24d and the compressor inflow passage 28b. The outflow side of the compressor 36 is in communication with the pressure tank 26 via the compressor outflow passage 28a, the second on-off valve 24b, and the tank connection main passage 16b. The working fluid on the air spring 12 side is pumped up by the compressor 36 and is pumped to the pressure tank 26.

  In the case of the vehicle height lowering control, the vehicle height lowering speed depends on the pumping speed of the working fluid by the compressor 36. That is, since the ECU 56 can arbitrarily adjust the output of the motor 34, the vehicle height lowering speed can be arbitrarily selected. Accordingly, the ECU 56 increases the output of the motor 34 when it is desired to increase the vehicle height lowering speed, and decreases the output of the motor 34 when it is desired to delay the vehicle height lowering speed. For example, when a passenger including a driver tries to leave the vehicle with the vehicle parked (stopped), it may indicate that the vehicle has transitioned to the resting state. In this case, when the passengers including the driver are around the vehicle, for example, after turning off the drive source of the vehicle and getting off the door and locking the door, the vehicle height is rapidly changed from the standard vehicle height. By lowering it, it is possible to produce an effect as if the vehicle stopped itself. In addition, when the vehicle height is lowered during traveling, stable traveling can be performed, and the vehicle height can be lowered within a speed range that does not cause a sense of incongruity while maintaining stable traveling.

  Further, the ECU 56 can adjust the descending amount of the vehicle height in the driving period of the compressor 36. For example, when a passenger including a driver leaves the vehicle with the vehicle parked (stopped), the vehicle height can be lowered so that the silhouette of the parked vehicle can be seen beautifully. Moreover, by lowering the vehicle height, it is possible to contribute to suppression of theft of wheels and the vehicle itself. In addition, when performing vehicle height descent control, it is desirable to detect that there is no obstacle on the lower surface side and the surroundings of the vehicle using a sensor or the like so that the vehicle is not damaged.

  FIG. 5 is a flowchart for explaining an example of the vehicle height adjustment control (lift control) of the vehicle height adjustment device 10. First, the ECU 56 checks whether or not there is a vehicle height increase request based on information acquired via the CAN at a predetermined control cycle, detection results acquired from each detection unit (sensor), or the like (S100). Then, when there is no increase request (N in S100), the ECU 56 instructs or confirms the stop of the compressor 36. At the same time, the ECU 56 instructs or confirms the closing of the first on-off valve 24a to the fourth on-off valve 24d (first on-off valve 24a, second on-off valve 24b, third on-off valve 24c, fourth on-off valve 24d), Instructing or confirming the closing of all the vehicle height adjusting valves 14 (S102). That is, the vehicle height state is maintained as it is, this flow is once ended, and the flow from S100 is repeated in the next control cycle.

  On the other hand, in S100, when there is a request for increase (Y in S100) and the compressor 36 is not being driven (N in S104), the ECU 56 confirms the stop of the compressor 36 and the first on-off valve 24a to the fourth on-off valve 24d ( The opening / closing of the first on-off valve 24a, the second on-off valve 24b, the third on-off valve 24c, and the fourth on-off valve 24d) is confirmed or instructed (S106). That is, the connection between the main flow path 16 and the compressor unit 30 (compressor 36) is cut off. On the other hand, when the compressor 36 is being driven in S104 (Y in S104), the ECU 56 confirms or instructs the driving of the compressor 36 and the closing of the second on-off valve 24b and the fourth on-off valve 24d (S108). That is, the main flow path 16 and the compressor unit 30 (compressor 36) are connected.

  In this state, the ECU 56 acquires (calculates) the pressure difference between the pressure tank 26 side and the air spring 12 side based on the detection results of the first pressure sensor 32a and the second pressure sensor 32b, and the pressure difference is a threshold value. It is determined whether this is the case (S110). That is, it is determined whether or not the pressure difference between the pressure tank 26 side and the air spring 12 side is equal to or greater than a threshold value that allows the working fluid to move favorably from the pressure tank 26 side to the air spring 12 side and be sent to the air spring 12. In S110, when the pressure difference is equal to or larger than a predetermined threshold (Y in S110), the ECU 56 confirms or instructs to stop the compressor 36, and also includes the first on-off valve 24a to the fourth on-off valve 24d (first on-off valve 24a, first on-off valve). The opening / closing of the second on-off valve 24b, the third on-off valve 24c, and the fourth on-off valve 24d) is confirmed or instructed (S112). Then, the ECU 56 instructs or confirms the opening of all the vehicle height adjusting valves 14 (S114), and supplies the working fluid to each air spring 12 to raise the vehicle height. That is, the vehicle height adjustment is executed in the differential pressure mode in which the working fluid is sent to each air spring 12 without using any power for transfer due to the pressure difference between the pressure tank 26 side and the air spring 12 side. And it returns to S100 and repeats the above-mentioned flow according to a control cycle.

  On the other hand, if the pressure difference is not greater than or equal to the predetermined threshold value in S110 (N in S110), the ECU 56 confirms or instructs the drive of the compressor 36 and confirms the closing of the second on-off valve 24b and the fourth on-off valve 24d. Alternatively, an instruction is given (S116). Then, the ECU 56 instructs or confirms the opening of all the vehicle height adjusting valves 14 (S114), supplies the working fluid to each air spring 12, and raises the vehicle height. That is, even when there is not a sufficient pressure difference, the vehicle height adjustment is executed in the forced pumping mode in which the working fluid is pumped from the pressure tank 26 by the compressor 36 and is pumped to send the working fluid to each air spring 12.

  In the case of the vehicle height lowering control, as described in FIG. 4, the ECU 56 drives the compressor 36 and opens the second on-off valve 24b and the fourth on-off valve 24d. The ECU 56 opens each vehicle height adjustment valve 14 to pump up the working fluid from the air spring 12 side and pump it to the pressure tank 26 to shorten the air spring 12 and lower the vehicle height to a desired value. Let Note that the pressure on the pressure tank 26 side can be increased by this control, and can be prepared for the next vehicle height increase control.

  FIG. 6 is a diagram illustrating another arrangement example of the first pressure sensor 32a and the second pressure sensor 32b. In the case of FIG. 1, the first pressure sensor 32 a and the second pressure sensor 32 b are shown as being integrated with the circuit valve block 24. On the other hand, in the case of FIG. 6, the first pressure sensor 32a and the second pressure sensor 32b are separately arranged. In other words, the first pressure sensor 32a is disposed corresponding to the pressure tank 26, and the second pressure sensor 32b is disposed corresponding to any one of the plurality of air springs 12 (vehicle height adjusting units).

  As described above, the first pressure sensor 32a is desirably disposed closer to the pressure tank 26 in order to detect the pressure state of the working fluid on the pressure tank 26 side. In the case of FIG. 6, the first pressure sensor 32 a is directly connected to the pressure tank 26. In this case, the pressure state of the pressure tank 26 can be detected more accurately. Further, the pressure tank 26 is generally disposed at a position where it is difficult to receive external impacts such as a stepping stone. Therefore, protection of the first pressure sensor 32a can be realized by disposing the first pressure sensor 32a close to the pressure tank 26. The first pressure sensor 32a can be selected as appropriate as long as the pressure state of the pressure tank 26 can be detected. For example, the first pressure sensor 32a is a tank like the first pressure sensor 32a indicated by a broken line in FIG. You may arrange | position in the connection main flow path 16b. In this case, the same effect as the above-described example can be obtained.

  Further, in FIG. 6, the second pressure sensor 32b is connected to the communication main flow path 16a for communicating the front wheel valve unit 18a and the rear wheel valve unit 18b. In this case, since the second pressure sensor 32b is disposed close to the air spring 12, the pressure state on the air spring 12 side can be detected more accurately. The front wheel valve unit 18a is disposed on the front wheel side, the rear wheel valve unit 18b is disposed on the rear wheel side, and the communication main flow path 16a connects between them. In this case, the connection position of the second pressure sensor 32b with respect to the communication main flow path 16a can be selected as appropriate. For example, the second pressure sensor 32b can be routed into the vehicle compartment or the trunk. That is, similarly to the first pressure sensor 32a, the second pressure sensor 32b can be disposed at a position where it is easy to avoid an external impact. As a result, there is an effect that the second pressure sensor 32b can be protected. In addition, if the 2nd pressure sensor 32b is a position which can detect the pressure state of the air spring 12, the arrangement position can be selected suitably. For example, a second pressure sensor 32b indicated by a broken line in FIG. 6 may be connected to the rear wheel valve unit 18b. As described above, when the front wheel valve unit 18a and the rear wheel valve unit 18b are the same 4-port type valve unit, one more port is used as the rear wheel valve unit 18b. In the example shown in FIG. 1, the remaining port is sealed with a plug cap. In the case of FIG. 6, this surplus port can be used as a connection port of the second pressure sensor 32b. As a result, it is possible to contribute to the common use of the valve unit and the simplification of the connection of the second pressure sensor 32b.

  Further, as shown in FIG. 6, by arranging the first pressure sensor 32 a and the second pressure sensor 32 b individually, the degree of arrangement freedom (design degree of freedom) is improved, and the first pressure sensor 32 a and the second pressure sensor 32 b are arranged. Even if the sensor 32b needs to be replaced, there is an advantage that the replacement work can be easily performed. Further, by arranging the first pressure sensor 32a and the second pressure sensor 32b separately from the circuit valve block 24, the circuit valve block 24 can be reduced in size. On the other hand, as shown in FIG. 1, by arranging the first pressure sensor 32a and the second pressure sensor 32b integrally with the circuit valve block 24, it is possible to contribute to reduction of the number of parts and improvement of assembly efficiency.

  Further, as described above, the vehicle height adjusting device 10 of the present embodiment includes the four first on-off valves 24a, the second on-off valves 24b, the third on-off valves 24c, and the fourth on-off valves 24d. The flow path is switched. As shown in FIGS. 1 to 4, the first on-off valve 24a, the second on-off valve 24b, the third on-off valve 24c, and the fourth on-off valve 24d use a simple and relatively inexpensive 2-port type on-off valve. can do. 2 to 4, the flow mode of the working fluid (flow path) depends on the combination of the open / close states of the first open / close valve 24a, the second open / close valve 24b, the third open / close valve 24c, and the fourth open / close valve 24d. Or flow direction) can be realized, which can contribute to cost reduction and simplification of the flow path design.

  In the above-described embodiment, when the vehicle height increase control is performed, the ECU 56 includes the first flow path system formed by opening the first on-off valve 24a and the fourth on-off valve 24d, the second on-off valve 24b, The example which selects at least one of the 2nd flow-path systems formed by valve opening of 3 on-off valve 24c was demonstrated. In another embodiment, when performing vehicle height increase control, the ECU 56 may always use both the first flow path system and the second flow path system. In this case, the flowability of the working fluid is improved, and the vehicle height increasing speed is increased as compared with the case where either one of the first flow path system and the second flow path system is selected, and quick vehicle height adjustment is possible. It becomes. In addition, the selection control of the on-off valve at the time of vehicle height increase control of the circuit valve block 24 becomes unnecessary, and the control logic is simplified.

  In the embodiment described above, in the case where the vehicle height adjustment control (upward control or lowering control) is performed, the example in which the air springs 12 are simultaneously lifted or lowered has been described. The air spring 12 may be adjusted. For example, if the rear wheel valve unit 18b side is closed and the front wheel valve unit 18a side is opened and the working fluid is supplied, the vehicle height adjustment only on the front wheel side can be performed by the air springs 12FR and 12FL on the front wheel side. it can. Similarly, if the front wheel valve unit 18a side is closed and the rear wheel valve unit 18b side is opened and the working fluid is supplied, the rear wheel side air springs 12RR and 12RL can be used only on the rear wheel side. High adjustment is possible. Further, if the vehicle height adjusting valves 14FR and 14RR are opened and the vehicle height adjusting valves 14FL and 14RL are closed and the working fluid is supplied, the vehicle height of only the air springs 12FR and 12RR on the right wheel side is provided. Can be adjusted. Conversely, if the vehicle height adjustment valves 14FL and 14RL are opened and the vehicle height adjustment valves 14FR and 14RR are closed and the working fluid is supplied, the vehicle height of only the air springs 12FL and 12RL on the left wheel side is obtained. Can be adjusted. Also in this case, since the vehicle height adjustment speed can be adjusted by selecting the first flow path system and the second flow path system of the circuit valve block 24, it is possible to obtain the same effect as the vehicle height adjustment for the four wheels simultaneously.

  Further, in the above-described embodiment, the closed type vehicle height adjusting device 10 has been described. However, a substantially similar device, for example, an atmosphere (outside air) is taken in and compressed by the compressor 36 via the pressure tank 26. The present invention can also be applied to a device that supplies air spring 12 and the same effect can be obtained.

  Although embodiments and modifications have been described in the present invention, these are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Vehicle height adjustment apparatus, 12 ... Air spring, 14, 14FR, 14FL, 14RR, 14RL ... Vehicle height adjustment valve, 16 ... Main flow path, 16a ... Communication main flow path, 16b ... Tank connection main flow path, 18a ... Front wheel valve Unit: 18b ... Rear wheel valve unit, 20 ... Main flow channel, 22 ... Sub flow channel, 24 ... Circuit valve block, 24a ... First on-off valve, 24b ... Second on-off valve, 24c ... Third on-off valve, 24d ... 4th on-off valve, 26 ... pressure tank, 26a ... tank body, 26b ... relief valve, 28a ... compressor outflow passage, 28b ... compressor inflow passage, 30 ... compressor unit, 32a ... first pressure sensor, 32b ... first 2 pressure sensors, 34 ... motor, 36 ... compressor, 38 ... dryer, 40 ... throttle mechanism, 40a ... orifice, 40b ... check valve, 42 ... -Safe valve, 44,46,48,54 ... check valve, 50, 52 ... filter, 56 ... ECU, 58 ... vehicle height sensor.

Claims (8)

A plurality of vehicle height adjustment units that are provided corresponding to the wheels of the vehicle body and adjust the vehicle height according to the supply and discharge of the working fluid;
A pressure tank for storing the working fluid;
A compressor for pumping the working fluid;
A plurality of on-off valves interposed between the vehicle height adjusting portion side and the pressure tank;
A first pressure detector provided upstream of the plurality of on-off valves;
A second pressure detector provided downstream of the plurality of on-off valves;
A control unit for controlling the compressor based on detection results of the first pressure detection unit and the second pressure detection unit;
A vehicle height adjustment device with   2. The vehicle height adjustment according to claim 1, wherein the first pressure detection unit detects a pressure of the working fluid on the pressure tank side, and the second pressure detection unit detects a pressure of the working fluid on the vehicle height adjustment unit side. apparatus. The controller is
The compressor is controlled by acquiring a pressure difference between the upstream side and the downstream side of the plurality of on-off valves based on a detection result of the first pressure detection unit and a detection result of the second pressure detection unit. Car height adjustment device.   4. The vehicle height adjustment device according to claim 1, wherein the first pressure detection unit and the second pressure detection unit are included in a valve body block formed by the plurality of on-off valves. 5.   The first pressure detection unit is disposed corresponding to the pressure tank, and the second pressure detection unit is disposed corresponding to any one of the plurality of vehicle height adjustment units. 4. The vehicle height adjusting device according to any one of items 3. The plurality of on-off valves are
A first on-off valve and a second on-off valve connected at one end side to the pressure tank, an end side connected to the outlet side of the compressor and the other end side of the second on-off valve, and the other end side of the vehicle height adjusting unit A third on-off valve connected to the side, and a fourth on-off valve having one end connected to the inflow side of the compressor and the other end of the first on-off valve and the other end connected to the vehicle height adjustment unit side Including
The controller is
When the working fluid is caused to flow from the pressure tank to the vehicle height adjusting unit due to a pressure difference therebetween, the first flow path system formed by opening the first on-off valve and the fourth on-off valve, and the first The vehicle height adjusting device according to any one of claims 1 to 5, wherein at least one of a second flow path system formed by opening a second on-off valve and the third on-off valve is selected. The plurality of on-off valves are
A first on-off valve and a second on-off valve connected at one end side to the pressure tank, an end side connected to the outlet side of the compressor and the other end side of the second on-off valve, and the other end side of the vehicle height adjusting unit A third on-off valve connected to the side, and a fourth on-off valve having one end connected to the inflow side of the compressor and the other end of the first on-off valve and the other end connected to the vehicle height adjustment unit side Including
The controller is
When the working fluid is caused to flow from the pressure tank to the vehicle height adjusting unit due to a pressure difference therebetween, the first flow path system formed by opening the first on-off valve and the fourth on-off valve, and the first The vehicle height adjusting device according to any one of claims 1 to 5, wherein a second flow path system formed by opening a second open / close valve and the third open / close valve is used.   A fluid regenerator and a throttle mechanism are arranged on the outflow side of the compressor, and the other end side of the second on-off valve and one end side of the third on-off valve are connected to each other and connected to the throttle mechanism. The vehicle height adjusting device according to claim 6 or 7.

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