JP2007051721A - Liquid-pressure source system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve clogged conditions of a filter prepared between a pump unit and reservoir in a liquid-pressure source system. <P>SOLUTION: A pumping liquid passage 72 connecting a reservoir 70 and pump unit 64 and return liquid passages 88 and 89 connecting supply liquid passages 74, and 40 from the pump unit to a liquid-pressure operation device 4 are provided, operating liquid flows backward the pumping liquid passage by leading it to the return liquid passage, and consequently, a pass-through flow in a reverse direction of the operation liquid against the filter 67 is realized. The pass-through flow is also realized either by making use of the operating liquid stored in an accumulator 66 and returned from the liquid-pressure operation device, or by operating the pump unit 64. The clogged conditions of the filter is recognized by the number of excessive continuous operations of the pump unit and liquid-pressure fluctuated situations of the operating liquid detected by a sensor 87. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle hydraulic pressure source system for supplying hydraulic fluid to an in-vehicle hydraulic device that is mounted on a vehicle and operates with hydraulic fluid pressure.

Vehicles are equipped with various on-board hydraulic actuators that operate by the hydraulic pressure of hydraulic fluid, such as brake devices and suspension devices, and hydraulic pressure as a system for supplying hydraulic fluid to these devices A source system is provided. This hydraulic pressure source system generally includes a reservoir in which hydraulic fluid is stored and a pump device that pumps hydraulic fluid from the reservoir and supplies the hydraulic fluid to the in-vehicle hydraulic pressure operating device. A filter is provided to prevent foreign matter or the like from being fed to the apparatus. The following patent document shows a system in which a filter is provided on the discharge side of a pump device, and a technique for dealing with clogging of the filter.
JP-A-2-249714

  The vehicle hydraulic pressure source system is generally provided with a filter on the suction side of the pump device instead of the discharge side filter or together with the filter. More specifically, a functional component called a strainer is disposed between the reservoir and the pump device. For such a filter on the suction side of the pump device, an effective measure against clogging is desired. The present invention has been made in view of such a situation, and provides a vehicle hydraulic pressure source system provided with effective treatment means for clogging of a filter disposed between a pump device and a reservoir. The task is to do.

  In order to solve the above-described problem, the vehicle hydraulic pressure source system of the present invention is a system in which a filter is provided in a pumping fluid passage that connects a reservoir and a pump device, and the working fluid is caused to flow backward in the pumping fluid passage. Thus, a counter-filter working fluid backflow device that realizes counter-filter backflow, which is a reverse flow of the working fluid to the filter, is provided.

  In the vehicle hydraulic pressure source system according to the present invention, when the counter-filter back flow is realized, when the filter provided on the suction side of the pump device is clogged, the clogging can be eliminated. Therefore, the system of the present invention can effectively cope with clogging of the filter.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following items, item (1) corresponds to claim 1, item (2) in claim 2, item (5) in claim 3, item (6) and (7), Are combined in claim 4, (8) in claim 5, (8) in claim 5, (9) through (11) in claim 6, and Equivalent to.

(1) A reservoir that stores hydraulic fluid, a pump device that discharges hydraulic fluid pumped from the reservoir, a pumping fluid passage that connects the reservoir and the pump device, and hydraulic fluid that is discharged from the pump device. A vehicle hydraulic pressure source system including a supply fluid passage that is supplied to an in-vehicle fluid pressure actuation device that is actuated by the hydraulic fluid, and a filter that is provided in the middle of the pumping fluid passage,
A vehicle hydraulic pressure source system including a counter-filter working fluid backflow device that realizes counter-filter backflow, which is a reverse flow of the working fluid with respect to the filter, by causing the working fluid to flow back through the pumping fluid passage.

  The mode described in this section is a mode related to a vehicle hydraulic pressure source system including means for dealing with so-called strainer clogging. By passing the hydraulic fluid in the reverse direction with respect to the filter, it is possible to effectively cope with clogging of the filter. In a hydraulic pressure source system mounted on a vehicle, for example, a pump device and a filter are often integrated, and even when the filter is clogged, measures such as quickly replacing the filter are taken. In general, it is generally necessary to rely on dismantling and cleaning work at the time of inspection or the like to eliminate clogging. Therefore, a merit provided with the said anti-filter hydraulic fluid backflow apparatus becomes a big thing. In addition, foreign substances that cause clogging are returned to the reservoir by the counter-filter backflow, but the counter-filter working fluid backflow device is used to eliminate clogging temporarily or relatively short-term. Can be effective. Incidentally, long-term clogging can be expected to be eliminated by providing a trap for foreign substances in the reservoir.

(2) The anti-filter hydraulic fluid backflow device is
A reflux liquid passage connecting the portion between the filter and the pump device in the pumped liquid passage and the supply liquid passage; a reflux liquid passage communication valve device that operates to connect the reflux liquid passage; And a valve control device for controlling the operation of the liquid passage communication valve device, and the counter-filter by the working fluid flowing from the supply liquid passage through the reflux liquid passage into the pumping liquid passage by communicating the reflux liquid passage The vehicle hydraulic pressure source system according to item (1), which realizes reverse flow.

  The aspect described in this section is an aspect in which a specific configuration of the anti-filter hydraulic fluid backflow device is limited. If the reflux liquid passage as described above is provided and the liquid passage is made to pass the working fluid to generate a counter-filter backflow, a counter-filter working fluid backflow device with a simple configuration can be realized. In addition, the “reflux liquid passage communication valve device” referred to in this section may be constituted by a single valve or may be constituted by a plurality of valves (the various types listed below). The same applies to the valve device).

  In addition, the expression “perform (by) by actuating” means that the target state is not realized when it is not operating, but the target state is realized by operating. To do. Therefore, the target state is realized by switching from the state where the valve device is not operated to the state where the valve device is operated by the “valve control device”. The valve device can be configured to include, for example, an electromagnetic valve, and the valve control device can be a control device that switches whether power is supplied to the electromagnetic valve. In that case, the state in which the valve device is operating may be a state in which electric power is supplied to the solenoid valve, and conversely, a state in which no electric power is supplied. That is, “acting” is a convenient concept used to express the function of the valve device, and is a concept regardless of the relationship with the state of energy supply to the valve device. Incidentally, the explanation items related to the “reflux liquid passage communication valve device” described here can be applied to various valve devices listed below with the same expression.

(3) The anti-filter hydraulic fluid backflow device is
A pump filter shut-off valve device that shuts off a portion between the pump and the pump device in the pumped liquid passage and the pump device by being actuated, and the valve control device includes the pump filter shut-off valve device; The vehicle hydraulic pressure source system according to item (2), which is controlled so as to be operated when the counter-filter reverse flow is realized.

  The “pump filter shut-off valve device” has a function of prohibiting the flow of hydraulic fluid from the reflux liquid passage to the pump device when realizing counter-filter reverse flow. Therefore, according to the aspect described in this section, even when the pump device is configured to include a pump having a structure that allows passage of hydraulic fluid when not in operation, such as a gear pump, it is effective. It is possible to realize a counter-filter reverse flow.

  (4) The vehicle hydraulic pressure source system according to (2) or (3), wherein the vehicle hydraulic pressure source system includes a backflow prohibiting valve device that is provided in the supply liquid passage and prohibits the backflow of hydraulic fluid to the pump device. Vehicle hydraulic pressure source system.

  If a “backflow prohibition valve device” is provided, backflow to the pump device is prohibited when realizing counter-filter backflow. For example, using an operating fluid from an accumulator or a hydraulic operation device described later When realizing the counter-filter backflow, the counter-filter backflow through the reflux liquid passage is surely realized.

(5) In the vehicle hydraulic pressure source system, the hydraulic fluid that is branched from the supply fluid passage to reach the reservoir and that returns to the reservoir from the in-vehicle hydraulic actuator through the supply fluid passage. With a return fluid passage
The anti-filter hydraulic fluid backflow device is
By providing a connection liquid passage that connects a location in the middle of the return liquid passage and a location between the filter and the pump device in the pumping liquid passage, the return liquid passage is formed by the connection liquid passage and the return liquid passage. A feedback fluid passage shut-off valve device configured to be configured and operated to shut off a portion in the middle of the feedback fluid passage and the reservoir;
The vehicle fluid according to any one of (2) to (4), wherein the valve control device controls the feedback fluid passage shut-off valve device to operate when the counter-filter reverse flow is realized. Pressure source system.

  In the hydraulic pressure source system, it is general that a fluid passage for returning the working fluid returned from the fluid pressure actuator to the reservoir is provided. Is an aspect in which is constructed. According to the aspect of this section, it is possible to easily construct a reflux liquid passage.

(6) The vehicle hydraulic pressure source system includes an accumulator that is provided in the supply liquid passage and stores hydraulic fluid.
The vehicle hydraulic pressure source system according to any one of (2) to (5), wherein the counter-filter working fluid backflow device realizes the counter-filter backflow by the working fluid from the accumulator.

  Many hydraulic pressure source systems are provided with an accumulator for accumulating pressure between a pump device and a hydraulic pressure actuating device. The aspect of this paragraph is an aspect which implement | achieves a counter-filter reverse flow using the hydraulic fluid stored by the accumulator in the pressure accumulation state, According to the aspect of this paragraph, it depends on the operating state of a hydraulic pressure operating apparatus. Without this, it is possible to realize an effective counter-filter backflow.

  (7) Item (2) to Item (6), wherein the vehicle hydraulic pressure source system realizes the counter-filter reverse flow by the hydraulic fluid returning from the in-vehicle hydraulic pressure operating device through the supply fluid passage. The vehicle hydraulic pressure source system according to any one of the above.

  The aspect of this section is one aspect that realizes counter-filter backflow by relying on the operation of the hydraulic actuator. Even when the accumulator is not provided, it is possible to realize effective counter-filter backflow.

(8) The counter-filter working fluid backflow device comprises:
A supply liquid passage shut-off valve device that shuts off the connection between the supply liquid passage and the reflux liquid passage and the in-vehicle hydraulic pressure operating device by being actuated, and the valve control device shuts off the supply liquid passage; The valve device is controlled to operate in the operating state of the pump device, and then the counter-filter back flow is realized by communicating the reflux liquid passage, according to the items (2) to (5) The vehicle hydraulic pressure source system according to any one of the above.

  The aspect of this term is an aspect which implement | achieves a counter-filter backflow through a reflux liquid channel | path by controlling the action | operation of a pump apparatus. The accumulator is not particularly required, and counter-filter backflow can be realized without depending on the operating state of the hydraulic actuator.

(9) The vehicle hydraulic pressure source system includes a filter clogging certifying device that certifies that the filter is clogged.
The vehicle fluid according to any one of (1) to (8), wherein the anti-filter working fluid reverse flow device realizes the anti-filter reverse flow based on the certification by the filter clogging certification device. Pressure source system.

  The aspect of this section is simply an aspect in which a device capable of detecting the occurrence of clogging of the filter is provided. According to the aspect of this section, for example, it can be recognized that clogging has actually occurred. Only in this case, counter-filter backflow can be realized, and an efficient system can be realized.

  (10) The filter clogging certification device shall certify that the filter is clogged based on the number of continuous operations exceeding the set time of the pump device. Hydraulic source system for vehicles.

  In general, when the strainer filter is clogged, the desired hydraulic fluid supply and hydraulic fluid pressure cannot be achieved quickly, and the operating time of the pump device in one operation becomes longer. The mode described in this section is a mode in which clogging of the filter is recognized using the phenomenon. In the hydraulic pressure source system, generally, continuous energization for a set time of the pump device or more is prohibited in order to prevent an overload of the pump device. That is, the continuous energization guard which is a function which interrupts | blocks electricity supply in such a case is provided. In the case where such a guard is provided, the aspect of this section indicates that the filter is clogged based on, for example, the number of times that the guard functions within the set period, that is, the frequency of overload, etc. It is possible to adopt a mode in which it is authorized.

  (11) The filter clogging recognition device is in a clogged state based on a hydraulic pressure change state of the hydraulic fluid supplied to the in-vehicle hydraulic pressure operating device when the pump device is operated. The vehicle hydraulic pressure source system according to (9) or (10), which is to be certified.

  As described above, when the filter is clogged, a phenomenon occurs in which the target hydraulic fluid pressure cannot be obtained or it takes a long time to obtain the hydraulic pressure. . The mode of this section is one mode of certifying the clogging state of the filter using the phenomenon. For example, it is possible to provide a pressure sensor that can detect the discharge pressure of the pump device and to identify clogging based on the detected value. The “hydraulic pressure change state” referred to in this section is a concept including the maximum achievable hydraulic pressure, the hydraulic pressure change gradient, and the like.

(12) The vehicle hydraulic pressure source system is
A vehicle height adjustment that is provided between the wheel and the vehicle body and includes an actuator that increases the separation distance between the wheel and the vehicle body by the action of the hydraulic fluid supplied from the hydraulic pressure source system, and functions as the vehicle-mounted hydraulic pressure operation device. It is supposed to supply hydraulic fluid to the device,
The vehicle according to (11), wherein the filter clogging certifying device certifies that the filter is clogged according to a different qualification standard for each mode in which the separation distance is increased by the actuator. Hydraulic pressure source system.

  The mode of this section is a mode specialized when the hydraulic pressure operating device is a vehicle height adjusting device. The vehicle height adjusting device is generally provided with a cylinder device called a so-called suspension cylinder that is arranged in parallel with a suspension spring, and the vehicle height is increased by supplying hydraulic fluid to the cylinder device. . In such a vehicle height adjusting device, for example, the higher the target vehicle height, the higher the hydraulic fluid pressure is required. The aspect of this section is an aspect for certifying the clogging state of the filter based on such an event peculiar to the vehicle height adjusting device. In the hydraulic pressure source system for supplying the hydraulic fluid to the vehicle height adjusting device, It becomes the aspect which can perform the recognition that it is clogged correctly. In addition, the “mode in which the separation distance is increased” in this section refers to, for example, each operation mode of the vehicle height adjustment device that makes the target vehicle height different, and the difference between the target vehicle height and the current vehicle height is different. This is a concept that means each operation mode of the vehicle height adjusting device.

(21) A reservoir that stores hydraulic fluid, a pump device that discharges hydraulic fluid pumped from the reservoir, a pumping fluid passage that connects the reservoir and the pump device, and hydraulic fluid that is discharged from the pump device Provided with an actuator for increasing a separation distance between the wheel and the vehicle body by the action of hydraulic fluid supplied through the supply liquid passage. In a vehicle hydraulic pressure source system for supplying hydraulic fluid to a vehicle height adjusting device,
A filter clogging certification device that is deployed in the system and certifies that the filter is clogged,
Based on the hydraulic pressure change state of the hydraulic fluid supplied to the vehicle height adjustment when the pump device is operated, the filter is in a clogged state according to different certification criteria for each mode of increase in the separation distance by the actuator. Filter clogging certification device that certifies that there is.

  The aspect of this section is an aspect of the claimable invention with different categories. According to the filter clogging recognition device of the aspect of this section, as described above, since the clogging state of the filter can be recognized based on an event peculiar to the vehicle height adjustment device, the hydraulic fluid is supplied to the vehicle height adjustment device. It is possible to accurately identify the clogging state of the filter with respect to the hydraulic pressure source system to be supplied.

  Hereinafter, embodiments of the claimable invention and modifications thereof will be described in detail with reference to the drawings. In addition to the following examples, the present invention is implemented in various modes including various modes modified and improved based on the knowledge of those skilled in the art, including the mode described in the above [Mode of Invention]. be able to. Note that the vehicle hydraulic pressure source system according to the embodiment forms part of the vehicle height adjustment system, and the hydraulic pressure source system according to the present embodiment will be described by describing the vehicle height adjustment system.

<Configuration of vehicle height adjustment system>
FIG. 1 conceptually shows a vehicle height adjustment system including the vehicle hydraulic pressure source system. The vehicle height adjustment system includes a hydraulic pressure source device 2 that supplies hydraulic fluid, and a vehicle height adjustment device 4 as an on-vehicle hydraulic pressure actuator that operates with the hydraulic pressure of the hydraulic fluid supplied from the hydraulic pressure source device 2. It is comprised including. The vehicle height adjusting device 4 includes four suspension cylinders 10 corresponding to the left front wheel FL, the right front wheel FR, the left rear wheel RL, and the right rear wheel RR, which include each of the four wheels and the vehicle body 12. (Strictly speaking, “a part of the vehicle body”) is provided in parallel with the suspension spring 13. The suspension cylinder 10 includes a housing 20, a piston 22 that can move inside the housing 20, and a piston rod 24 that has one end connected to the piston 22 and the other end extending from the housing 20. . The suspension cylinder 10 has one end portion of the piston rod 24 extending from the housing 20 connected to the wheel, and the end portion of the housing 20 on the side where the piston rod 24 does not extend is connected to the vehicle body 12. As the wheel moves up and down with respect to 12, it expands and contracts. Incidentally, the vehicle height adjustment system is configured as a hydraulic system using hydraulic fluid as hydraulic fluid.

  In each of the suspension cylinders 10, the interior of the housing 20 is divided into two operations by a piston 22, a hydraulic fluid chamber 26 on the side where the piston rod 24 does not exist and a hydraulic fluid chamber 28 on the side where the piston rod 24 exists. Divided into liquid chambers. The piston 22 is provided with a communication passage 30 that has a throttle and communicates the two hydraulic fluid chambers 26, 28. When the wheel moves up and down with respect to the vehicle body 12, the piston 22 moves in the housing 20. The hydraulic fluid can move through the communication path 30. The hydraulic fluid chamber 26 of each suspension cylinder 10 is provided with a port through which hydraulic fluid can flow in and out, and an individual supply path 40 is connected to the port via a variable throttle valve 32. Yes. With such a structure, the hydraulic fluid flows into and out of the hydraulic fluid chamber 26 in order to cope with a change in the total volume of the hydraulic fluid chambers 26 and 28 accompanying the movement of the piston 22 in the housing 20. In addition, the suspension cylinder 10 is configured to generate a damping force with respect to the vertical movement of the wheels by the throttle and the variable throttle valve 32 provided in the communication path 30, that is, to function as a shock absorber. The variable throttle valve 32 has a variable throttle amount and has a function of adjusting the damping force generated by the suspension cylinder 10. In addition, the individual supply path 40 is a generic name, and when it is necessary to clarify which wheel it is for, a subscript indicating a wheel position may be added as shown in the figure.

  Each of the four individual supply paths 40 is provided with a first accumulator 42 and a second accumulator 44 corresponding to each suspension cylinder 10, and a spring constant switching valve 46 is provided corresponding to the second accumulator 44. Yes. Each of the first accumulator 42 and the second accumulator 44 functions as a buffer for hydraulic fluid that flows into and out of the suspension cylinder 10 as the wheel moves up and down, and also functions as a spring. Therefore, the suspension cylinder 10 and the two accumulators 42 and 44 constitute one spring. The spring constant of the spring is changed by switching the presence / absence of communication between the second accumulator 44 and the suspension cylinder 10 by the spring constant switching valve 46 which is a normally open electromagnetic on-off valve. The spring constant of the second accumulator 44 is smaller than that of the first accumulator 42 (the first accumulator 42 is a high pressure accumulator and the second accumulator 44 is a low pressure accumulator. The spring constant of the spring is small when the spring constant switching valve 46 is open, and the spring constant is large when the spring constant switching valve 46 is closed.

  The hydraulic pressure source device 2 is connected to each hydraulic fluid chamber 26 of the suspension cylinder 10 corresponding to each wheel via an individual supply path 40 corresponding to each of the hydraulic fluid chambers 26. The hydraulic pressure source device 2 includes a pump device 64 including a pump 60 and a pump motor 62, a pressure accumulator 66, a strainer 68 incorporating a filter 67, a reservoir 70, and the like. The reservoir 70 and the pump device 64 are connected by a pumping path 72 that is a pumping liquid path, and the strainer 68 is provided in the middle of the pumping path 72. The strainer 68 has a function of preventing foreign matter or the like mixed in the hydraulic fluid from being fed to the vehicle height adjusting device 4 or the like through the pump 60 or the pump 60 by the filter 67 included in the strainer 68. Between the strainer 68 and the pump device 64 is provided a pumping path control valve 73 which is a normally open electromagnetic on-off valve. The pumping path control valve 73 functions as a pump filter shutoff valve device. The pumping path 72 is in a communicating state when the valve is open, and the pumping path 72 is closed when the valve is closed. A main supply path 74 is connected to the discharge side port of the pump 60, and the main supply path 74 is branched and connected to the four individual supply paths 40 described above. A supply fluid path from the fluid pressure source device 2 to the vehicle height adjusting device 4 is constituted by the supply passage 40. A check valve 80 as a check valve device is interposed in the main supply passage 74, and a silencing accumulator 82 is connected, and the accumulator 66 for pressure accumulation is a normally closed electromagnetic on-off valve. It is connected via a certain pressure accumulation control valve 86. A pressure sensor 87 is provided between the pressure accumulator 66 and the pressure accumulation control valve 86.

  Further, the hydraulic pressure source device 2 is connected to the main supply passage 74 and the reservoir 70 by bypassing the pump device 64, and serves as a return fluid passage for guiding the hydraulic fluid returning from the vehicle height adjusting device 4 to the reservoir 70. Return path 88 is provided. A connection path 89 is provided as a connection liquid path for connecting the return path 88 and a portion of the draw-up path 72 between the strainer 68 and the draw-up path control valve 73, and the return path 88 includes a connection path 89 and a connection path 89. A feedback path control valve 90, which is a normally closed electromagnetic on-off valve, is provided at a position closer to the reservoir 70 than the connection point of FIG. Is provided. The feedback path control valve 90 functions as a feedback path control valve shut-off valve device. The feedback path 88 is in a communication state when the valve is open, and the feedback path 88 is shut off when the valve is closed. The connection path control valve 91 is opened. In the valve state, the connection path 89 is in a communicating state, and in the valve closed state, the connection path 89 is in a cutoff state.

  Each individual supply path 40 is provided with an individual control valve 100 which is a normally closed electromagnetic on-off valve, and a connection passage 102F for connecting the individual passages 40FL and 40FR corresponding to the left and right front wheels, and an individual corresponding to the left and right rear wheels. The connection passage 102R that connects the passages 40RL and 40RR is provided with communication control valves 104F and 104R (sometimes collectively referred to as “communication control valve 104”), which are normally closed electromagnetic on-off valves. The individual control valve 100 functions as a supply liquid passage cutoff valve device, and makes the individual supply passage 40 in a communication state when the valve is open and shuts off the individual supply passage 40 when the valve is closed. When the communication control valve 104 is in the open state, the vehicle height with respect to the left and right wheels can be changed at the same time, and when the communication control valve 104 is in the closed state, it can be controlled separately. Further, the vehicle height for each of the four wheels can be independently adjusted by opening / closing control of the individual control valve 100 when the communication control valve 104 is closed. It should be noted that the individual control valve 100 is a generic name, and when it is necessary to clarify which wheel it is for, as shown in the figure, as in the case of the individual passage 40, a subscript indicating the wheel position. May be attached.

  From the above configuration, in this vehicle height adjustment system, the suspension cylinder 10 may be referred to as a distance in the vehicle height direction (hereinafter referred to as “separation distance”) between the wheel and a part of the vehicle body 12 on which the wheel is provided. ) And the hydraulic pressure source device 2 drives the suspension cylinder 10 to change the vehicle height. More specifically, in the vehicle height adjustment when it is necessary to raise the vehicle height (hereinafter sometimes referred to as “vehicle height increase adjustment”), the pressure accumulation control valve 86 is opened and the pump device 64 is operated. When the four individual control valves 100 are opened, the hydraulic fluid is pumped from the reservoir 70 and flows into the suspension cylinders 10 through the individual supply paths 40. The state is maintained until the actual vehicle height reaches the target vehicle height. When the actual vehicle height reaches the target vehicle height, the four individual control valves 100 are closed, and then detected by the pressure sensor 87. The hydraulic pressure of the accumulator 66 for pressure accumulation is set standard pressure (set as a pressure that does not cause a decrease in the vehicle height due to the outflow of hydraulic fluid from the suspension cylinder 10 in the next vehicle height increase adjustment) In this case, the pressure accumulation control valve 86 is closed and the operation of the pump device 64 is stopped. On the contrary, in the vehicle height adjustment when the vehicle height needs to be lowered (hereinafter sometimes referred to as “vehicle height decrease adjustment”), the feedback path control valve 90 is opened and the four individual control valves 100 are opened. Is opened, the hydraulic fluid is returned from the suspension cylinder 10 to the reservoir 70. This state is maintained until the actual vehicle height reaches the target vehicle height. When the actual vehicle height reaches the target vehicle height, the four individual control valves 100 are closed and the return path control valve 90 is closed. To be spoken. Further, in the vehicle height adjustment when there is no need to change the vehicle height (hereinafter sometimes referred to as “vehicle height maintenance adjustment”), the pump device 64 is stopped, and the pressure accumulation control valve 86 and the feedback path control valve 84 are stopped. , All of the four individual control valves 100 are closed.

  The above explanation is a case where the common vehicle height adjustment is performed for all four wheels, but when adjusting the vehicle height individually for the four wheels, the individual control valves 100 are individually controlled as described above. In the case where the vehicle height is adjusted in common for the left and right wheels on the front wheel side and the rear wheel side, and individually on the front wheel side and the rear wheel side, the communication control valve 104 is opened. Adjust it. In the following description, in order to avoid redundancy of the specification, a case where the vehicle height adjustment is performed in common for all four wheels will be described as an example.

  The operation of the suspension cylinder 10, that is, the control of the above-described hydraulic pressure source device 2 (specifically, each control valve, pump device 64, etc. constituting it) is controlled by a vehicle height adjustment electronic control unit (vehicle height adjustment ECU) 120. Done. The vehicle height adjustment ECU 120 is an electronic control device that includes a computer and a drive circuit. In addition, the vehicle height adjustment system is provided with various switches, various sensors for detecting the operation state and traveling state of the vehicle as information that depends on the control. Specifically, for each wheel, four vehicle height sensors 130 (indicated as “L” in the figure) for detecting the distance between each wheel and the vehicle body are provided, and in the vehicle interior. Uses a seating sensor 131 (indicated as “W” in the figure) that detects the presence or absence of an occupant at the seating position corresponding to the seating position of the occupant, and hydraulic fluid that returns from the vehicle height adjustment device 4 described later. Specific clogging elimination operation prohibition switch 134 (in the figure, indicated as “KSW”) for prohibiting the removal of clogged filter clogging, and a vehicle height change switch 136 (in the figure, for changing the vehicle height by the driver's operation) , “PSW”). Further, in the luggage room, a luggage sensor 138 (indicated as “S” in the figure) for detecting the presence / absence of luggage is provided. These switches, sensors, and the like are also connected to the vehicle height adjustment ECU 120.

  In this vehicle height adjustment system, the set vehicle height is the set standard vehicle height (Mid vehicle height) that is normally used when driving on normal roads, and the set vehicle height (Hi vehicle height) set as the vehicle height higher than the set standard vehicle height. ), A set low vehicle height (Low vehicle height) set as a vehicle height lower than the set standard vehicle height is set, and a desired set vehicle height is selectively set by the operation of the vehicle height change switch 136 by the driver. It can be changed to. This vehicle height change switch 136 issues a command for shifting the set vehicle height to a higher set vehicle height or a lower set vehicle height, that is, a vehicle height increase command or a vehicle height decrease command. In this vehicle height adjustment system, in principle, the vehicle height is adjusted so that the set vehicle height is based on the command. Further, regardless of the set vehicle height selected by the driver, the vehicle height is automatically adjusted to the Mid vehicle height when the vehicle traveling speed exceeds the set speed. Furthermore, it has a function of automatically adjusting the deviation of the vehicle height from the set vehicle height according to the vehicle body weight, more specifically, the load weight described later. The details of these vehicle height adjustments are not described here because they are not directly related to the claimable invention.

<Countermeasures against filter clogging>
In the present vehicle height adjustment system, as described above, the strainer 68 is provided to prevent foreign matters and the like from being fed. The filter 67 of the strainer 68 is expected to become clogged with foreign matter and the like as the system operating time elapses. If such a clogged state of the filter 67 is left, proper vehicle height adjustment cannot be performed, and the overload state of the pump motor 62 becomes chronic. Therefore, in this vehicle height adjustment system, a process for certifying the clogging state of the filter 67 by monitoring a phenomenon caused by the clogging of the filter 67 (hereinafter, sometimes referred to as “clogging state recognition process”). When it is determined that the clogged state is detected, a process for eliminating the clogged state (hereinafter, also referred to as “clogged state eliminating process”) is executed.

i) Approval of filter clogging condition When the filter 67 is clogged, the pumping speed of the hydraulic fluid is decreased by decreasing the pumping speed of the hydraulic fluid. When supplying the hydraulic fluid having the set pressure to the adjusting device 4, specifically, when the pressure of the hydraulic fluid in the suspension cylinder 10 is set to the set pressure, the operation time of the pump device 64 becomes long. . Therefore, it is possible to recognize that the filter 67 is clogged by monitoring the operation time of the pump device 64 once.

  In this vehicle height adjustment system, in order to prevent overloading of the pump device 64, more specifically, overloading of the pump motor 62, the pump motor 62 is moved to the pump motor 62 when the pump motor 62 is continuously operated for a predetermined time or more. Is provided with a function of shutting off the energization, that is, a function of operating a so-called continuous energization guard. Therefore, this vehicle height adjustment system uses this function to monitor the number of times this continuous energization guard is activated (hereinafter sometimes referred to as “continuous energization guard count”), and the continuous energization guard count is the set threshold number of times. When it becomes (for example, 10 times) or more, the filter 67 is recognized as being clogged. In other words, the clogging state recognition process based on the number of times the pump device 64 has been continuously operated over the set time is performed to recognize that the filter 67 has become clogged. In addition, since the authorization process based on the number of continuous energization guards is a process based on the operation frequency of the continuous energization guard within a set period (for example, one month), the accumulated number of continuous energization guards is determined for each period. Reset to.

  As described above, when the pump device 64 is operated to obtain the target hydraulic fluid pressure of the suspension cylinder 10, the time until the target hydraulic fluid pressure is reached when the filter 67 is clogged. Takes a long time. In other words, the change gradient of the discharge fluid pressure of the pump device 64 becomes small. Therefore, it is possible to recognize that the filter 67 has become clogged by monitoring the hydraulic pressure change state of the hydraulic fluid during the operation of the pump device 64 during the vehicle height increase adjustment. Therefore, in the present vehicle height adjustment system, the hydraulic pressure of the hydraulic fluid detected by the hydraulic pressure sensor 87 after the set time elapses from the time when the vehicle height increase adjustment is started is recognized to be clogged. It is determined that the filter 67 is clogged when the hydraulic pressure is used as a basis (hereinafter sometimes referred to as “base hydraulic pressure”) and the hydraulic pressure is equal to or lower than a set threshold pressure. That is, the authorization process that relies on the adjustment for increasing the vehicle height is executed. The set time is specific when the vehicle height is adjusted from a certain vehicle height to a certain vehicle height in a state in which no foreign matter adheres to the filter 67 (hereinafter sometimes referred to as “filter clean state”). Actually, the time is shorter than the time required to adjust the vehicle height from one of the Low vehicle height or Mid vehicle height to Mid vehicle height or Hi vehicle height (about half of the time in this system). It is said that.

FIG. 2 shows a hydraulic pressure change state of the hydraulic fluid pressure when the vehicle height increase adjustment is performed for a certain vehicle weight. In this figure, the vertical axis represents the hydraulic fluid pressure P, the horizontal axis represents the time t, and P _L , P _M , and P _H are required at the Low vehicle height, the Mid vehicle height, and the Hi vehicle height, respectively. The hydraulic pressure (hereinafter sometimes referred to as “necessary hydraulic pressure”). The solid line represents the fluid pressure change state in the filter clean state. In this state, when the vehicle height increase adjustment is performed from the low vehicle height, the hydraulic fluid pressure becomes P _L0 after the set time Δt has elapsed. Here, when foreign matter or the like adheres to the filter 67, the hydraulic pressure change gradient as shown by the solid line cannot be obtained, and the hydraulic pressure change gradient becomes small. If the hydraulic pressure change state which is an allowable limit is indicated by a broken line, in that state, the working hydraulic pressure becomes P _LS after the set time Δt has elapsed. Therefore, if the hydraulic fluid pressure after the set time Δt has elapsed from the vehicle height increasing adjustment starting grounds pressure Pderuta _t, the rationale pressure Pderuta _t is, if a value below the P _LS is閾液pressure P _S, It becomes possible to recognize that the filter 67 is clogged.

However, as a phenomenon peculiar to the vehicle height adjustment system, the threshold hydraulic pressure P _S varies depending on from which vehicle height the vehicle height increase adjustment is performed. In other words, from the relationship of the shared load between the suspension spring 13 and the suspension cylinder 10, the required hydraulic fluid pressure is higher when the vehicle height is higher than when the vehicle height is low. The ground hydraulic pressure is different depending on whether the increase is adjusted. Specifically, when the vehicle height is adjusted from the Mid vehicle height, the hydraulic pressure change state that becomes the allowable limit is a hydraulic pressure change state as shown by a one-dot chain line in FIG. pressure P _S is the P _MS. In view of this phenomenon, in the present vehicle height control system, depending on whether the vehicle height increasing adjustment is made from which the vehicle height, the閾液pressure P _S is changed. That is, the certification standard for authorizing the clogged state of the filter 67 is changed according to the aspect in which the distance between the wheel and the vehicle body is increased.

Further, as the vehicle height adjustment system peculiar phenomenon, body weight, In detail, the loading weight of the vehicle by (occupant weight of cargo that including baggage), and that the閾液pressure P _S is different. In FIG. 3, the relationship between the vehicle-mounted weight for every setting vehicle height and required hydraulic fluid pressure is shown. As can be seen from this figure, the load received by the suspension cylinder 10 increases even if the load is increased, so that the threshold hydraulic pressure needs to be changed according to the required hydraulic pressure P _0. There is. The loading weight M is assumed to be Mh for the occupant weight per person and Mp for the load mass when loaded, and then the number of passengers N detected by the seating sensor 131 and the load detected by the luggage sensor 138. Based on the presence / absence of loading K (0 when there is no luggage, 1 when there is luggage), it is estimated according to the following equation and determined in a simulated manner.
M = Mh × N + Mp × K

In consideration of the above, in the present vehicle height control system,閾液pressure P _S to parameter the vehicle height and load weight M to start the vehicle height increasing adjustment, the height adjustment ECU 120, are stored as map data and, in the certification process of the reliance on the clogging state to the vehicle height increasing adjustment, the height increasing adjustment starting vehicle height, the閾液pressure P _S corresponding to the load weight M, elected from the map data, the selection than that which is to be compared with the閾液pressure P _S and the rationale pressure Pderuta _t was.

In this vehicle height adjustment system is certified process clogging state of relying on the vehicle height increasing adjustment is being done by comparison with the grounds hydraulic Pderuta _t and閾液pressure P _S, such an approach It is also possible to adopt a certification process for authorizing that the vehicle is clogged according to the time required from the start of the vehicle height increase adjustment to the completion of the vehicle height increase adjustment. Specifically, the required time is adjusted to increase the vehicle height from the Low vehicle height to the Mid vehicle height, adjust the vehicle height increase from the Mid vehicle height to the Hi vehicle height, and adjust the vehicle height increase from the Low vehicle height to the Hi vehicle height. In each of the above, when the threshold times Δt _LM , Δt _MH , and Δt _LH are exceeded, it is possible to determine that the filter 67 is clogged. Even when such a certification process is adopted, the certification standard is changed based on an aspect in which the distance between the wheel and the vehicle body is increased. Also, when such a certification process is adopted, it is desirable to change the threshold time according to the loaded weight M, as in the previous certification process.

ii) Eliminating filter clogging In the clogging state elimination process of the filter 67 in the vehicle height adjustment system, the direction in which the hydraulic fluid passes when the vehicle height increase adjustment or the like is performed with respect to the filter 67 is reversed. Let the hydraulic fluid pass through. In other words, the clogging is eliminated by a passage flow in a direction opposite to the normal direction (hereinafter sometimes referred to as “counter-filter reverse flow”). That is, the processing is intended to return the foreign matter or the like adhering to the filter 67 to the reservoir 70 by counter-filter reverse flow. Specifically, the pumping path control valve 73 and the feedback path control valve 90 are closed, and the connection path control valve 91 is opened, and the working fluid is introduced into the feedback path 88, so that Backflow is realized, and the clogged state of the filter 67 is eliminated. More specifically, in the clogging state elimination processing in the vehicle height adjustment system, counter-filter backflow is realized in three processing modes. The clogging state elimination processing of these three modes will be named “accumulator usage elimination processing”, “feedback flow usage elimination processing”, and “pump operation usage elimination processing”, respectively. And the operation of the hydraulic pressure source device 2 in the processing will be described.

  In the accumulator utilization elimination process, the hydraulic fluid stored in the pressure accumulator 66 is utilized. As described above, the hydraulic fluid is stored in the pressure accumulator 66 in a pressurized state. Therefore, in many cases, the hydraulic fluid pressure of the pressure accumulator 66 is relatively high, and in such a case, the hydraulic fluid stored in the pressure accumulator 66 is used to realize counter-filter reverse flow. . Specifically, when the hydraulic pressure of the accumulator 66 for pressure accumulation detected by the hydraulic pressure sensor 87 is equal to or higher than the set pressure, the accumulator utilization elimination process is executed. In the operation of the hydraulic pressure source device 2 in this process (hereinafter sometimes referred to as “accumulator use cancellation processing operation”), the pumping path control valve 73 and the feedback path control valve 90 are in a state where the pump apparatus 64 is stopped. The individual control valve 100 is closed, and the connection path control valve 91 and the pressure accumulation control valve 86 are opened. In the present elimination process, the counter-filter backflow is realized by such an operation, and the clogged state of the filter 67 is eliminated. The flow of the hydraulic fluid at this time is shown in FIG.

  The feedback flow utilization elimination process is executed when the hydraulic pressure of the accumulator 66 for pressure accumulation is less than the set pressure, and counter-filter reverse flow using the hydraulic fluid returned from the vehicle height adjusting device 4 is realized. When the vehicle height is Hi vehicle height, there is a relatively high pressure hydraulic fluid in the suspension cylinder 10 and the vehicle height is higher than the Mid vehicle height, which is the vehicle height commonly used. If the person requests the cancellation process, even if the vehicle height decreases due to the process, it is considered that there is little adverse effect. For this reason, the return flow use elimination processing is executed on condition that the vehicle height is Hi vehicle height and that the specific clogging elimination operation prohibition switch 134 described above is not in the ON state. Is done. In the operation of the hydraulic pressure source device 2 in this cancellation processing (hereinafter, sometimes referred to as “return flow utilization cancellation processing operation”), the pressure accumulation control valve 86 is not opened, and the pump device 64 is stopped. The pumping path control valve 73 and the feedback path control valve 90 are closed, and the individual control valve 100 and the connection path control valve 91 are opened. In the present elimination process, the counter-filter backflow is realized by such an operation, and the clogged state of the filter 67 is eliminated. The flow of the hydraulic fluid at this time is shown in FIG.

  The pump operation use cancellation process is executed when the above two cancellation processes cannot be executed. In the pump operation use elimination processing, the pump device 64 is operated, and the working fluid resulting from the operation is introduced into the return path 88, thereby realizing counter-filter backflow. In the operation of the hydraulic pressure source device 2 in this cancellation process (hereinafter, sometimes referred to as “pump operation utilization cancellation processing operation”), (a) the individual control valve 100, the connection path control valve 91, and the feedback path control valve 90 are closed. In the state where the pumping-up path control valve 73 is opened and the pump device 64 is operated, the hydraulic fluid is pumped up from the reservoir 26, and then (b) the pump device 64 is stopped. At the same time, the pumping path control valve 73 is closed and the connection path control valve 91 is opened. In the present elimination process, the counter-filter backflow is realized by such an operation, and the clogged state of the filter 67 is eliminated. The flow of the hydraulic fluid at this time is shown in FIG.

  In this vehicle height adjustment system, counter-filter backflow is realized in various aspects as described above. The liquid passage for realizing the counter-flute back flow includes a part of the return path 88 and a connection path 89, and the liquid path is located between the filter 67 and the pump device 64 in the pumping liquid path. And a recirculating liquid passage communicating valve device for connecting a recirculating liquid passage with a connecting passage control valve 91 provided in the connecting passage 89. As a function.

  Note that the above-described filter clogging state elimination processing is executed at a time other than when the clogging state of the filter 67 is recognized by the above-described filter clogging state recognition processing. More specifically, from the viewpoint of preventing clogging of the filter 67, in this vehicle height adjustment system, the accumulated time (hereinafter referred to as the pump device 64) is operated regardless of whether the filter 67 is clogged or not. In this case, the processing is executed every set time (for example, 30 hours).

<Clogging countermeasure program>
In this vehicle height adjustment system, control of the general operation of the system related to vehicle height adjustment, such as increase / decrease and maintenance of vehicle height, is performed by the vehicle height adjustment ECU 120 executing a vehicle height adjustment program. In the control by this program, a current vehicle height flag F that is a flag indicating the current vehicle height (which vehicle height is set) and a target vehicle height (if the vehicle height is changed, which vehicle height is set) The target vehicle height flag F ^* which is a flag indicating whether or not to change the vehicle height is used, and the vehicle height adjustment based on the flags F ^* and F is executed. The flag values of the flags F ^* and F are set to 0, 1, or 2, respectively, which correspond to the Low vehicle height, the Mid vehicle height, and the Hi vehicle height, respectively. Incidentally, the current vehicle height flag F is also used in processing for dealing with clogging of the filter 67 described later. Note that the flag values of these flags F ^* and F are maintained without being reset even while the ignition switch is in the OFF state.

  The vehicle height adjustment ECU 120 also executes a clogging countermeasure program, which is a program for performing clogging state recognition processing, clogging state elimination processing, etc. of the filter 67 in a time-sharing manner in parallel with the vehicle height adjustment program. Have been to. This clogging countermeasure program is a program whose flowchart is shown in FIG. 7, and is repeatedly executed at short time intervals (for example, several m to several tens of msec) while the ignition switch is in the ON state. Hereinafter, a flow of processing performed by executing the clogging countermeasure program will be described in detail with reference to the flowchart.

  First, in step 1 (hereinafter simply referred to as “S1”, the same applies to other steps), a clearing process execution flag G, which is a flag indicating whether or not a clogging state clearing process described later is necessary, is set to 0. It is determined whether or not. This flag G is set to 0 when the execution of the cancellation process is not required, and is set to 1 when the execution is required. When the flag value is 0, the number of continuous energization guards is set in the subsequent S2. It is determined whether or not the threshold number α is greater than or equal to. The number of continuous energization guards is stored in the ECU 120, and is reset on the condition that the set period described above has elapsed and a clogged state elimination processing subroutine described later is executed. If it is determined that the continuous energization guard number is equal to or greater than the set threshold number α, the cancellation process execution flag G is set to 1 in S6, and if it is determined that the number is less than the set threshold number α, in S3, It is determined whether the pump device cumulative operation time is equal to or greater than a set threshold time β. The pump device cumulative operation time is measured by the ECU 120, and is reset on condition that a clogging state elimination processing subroutine described later is executed. If it is determined that the pump device cumulative operation time is equal to or greater than the set threshold time β, the elimination process execution flag G is set to 1 in S6, and if it is determined that the pump processing cumulative operation time is shorter than the set threshold time β, in S4. Then, it is determined whether or not the above-described vehicle height increase adjustment is performed.

If it is determined in S4 that the vehicle height increase adjustment has been performed, that is, if the vehicle height increase adjustment has been started, in S5, the hydraulic fluid pressure-based clogging state recognition processing subroutine shown in the flowchart of FIG. Is executed. In this subroutine, first, the time after the vehicle height increase adjustment is started is measured by the time counting process of S21 and S22, and the elapse of the set time is awaited. When the set time has elapsed, specifically, when the time counter T _C becomes the set value T _0, in S23, grounds pressure Pderuta _t detected by hydraulic pressure sensor 87 is acquired. In subsequent S24 and S25, the flag value of the current vehicle height flag F is acquired, and the loaded weight M is estimated from the seating sensor 131 and the luggage sensor 138 based on the above formula. Based on the flag value and the loaded weight M their current vehicle height flag F, in S26, FIG. 2 stored in the vehicle height adjusting ECU 120, is referenced map data corresponding to FIG. 3, elected閾液pressure P _S Is done. In the next S27, it is compared with the rationale pressure Pderuta _t and閾液pressure P _S, when grounds pressure Pderuta _t is less閾液pressure P _S, at S28, is recognized as the filter 67 is clogged state Thus, the cancellation process execution flag G is set to 1. If the grounds pressure Pderuta _t is determined to exceed the閾液pressure P _S in S27 is certified as a clogging state is not performed. S27, S28 after the completion, in S29, the time counter T _C is reset, execution of this subroutine is ended. In this subroutine, in order to simplify the explanation, the authorization process is performed on the assumption that the vehicle height increase adjustment is continued until the target vehicle height is reached.

  In the above subroutine, when it is determined that the filter 67 is clogged, or when it is determined that the accumulated operation time of the pump device is equal to or longer than the set threshold time β, the elimination process execution flag G is set to 1. In these cases, the processes after S7 are executed based on the determination in S1. When it is determined that the clogging state is present, information indicating that the clogging state is recognized is transmitted to the diagnosis ECU 150 connected to the vehicle height adjustment ECU 120. This information is stored in the diagnosis ECU 150 and is used as ground information for determining whether or not the filter 67 should be cleaned, for example, in a periodic inspection of the vehicle.

  The processes after S7 are a clogging state elimination process and a series of processes related to the process. In the series of processes, first, in step S7, the vehicle height adjustment is prohibited in order to execute the clogging state elimination process. Specifically, the execution of the vehicle height adjustment program described above is stopped. In subsequent S8, as a preparation for the clogging state elimination processing, the pressure accumulation control valve 86, the feedback path control valve 90, and the individual control valve 100 are closed, and the pump device 64 is stopped. “Open valve” and “closed valve” of the control valves 86, 90, 100, etc. mean not only changes between the open state and the closed state but also those states are maintained. The “operation” and “stop” of the pump device 64 mean not only a change between the operation state and the stop state but also that these states are maintained.

After the processing of S7 and S8 is executed, the clogging state elimination processing subroutine shown in the flowchart of FIG. 9 is executed in S9. This subroutine, in S31, whether the accumulator pressure P _A is the hydraulic accumulator accumulator 66 detected by the pressure sensor 87 is set threshold pressure γ above are determined. When it is equal to or higher than the set threshold pressure γ, an accumulator utilization cancellation processing operation subroutine is executed in S32. When the accumulator pressure P _A is smaller than the set threshold pressure γ, in S33, to execute the clogging state eliminating process that reflects the intention of the driver, whether a specific plugging eliminating operation inhibition switch 134 is ON Is judged. When the specific clogging elimination operation prohibition switch 134 is in the OFF state, it is determined in S34 whether or not the current vehicle height detected by the vehicle height sensor 130 is the Hi vehicle height. When the vehicle height is Hi, the return flow utilization cancellation processing operation subroutine is executed in S35. When it is determined in S33 that the specific clogging elimination operation prohibition switch 134 is in the ON state, or in S34, it is determined that the current vehicle height detected by the vehicle height sensor 130 is other than the Hi vehicle height. If so, a pump operation use cancellation processing operation subroutine is executed in S36.

The accumulator utilization cancellation processing operation subroutine of S32 is a subroutine whose flow chart is shown in FIG. 10. In the processing of this subroutine, first, in S41, the connection path control valve 91 and the pressure accumulation control valve 86 are opened, and the pump. Raise the control valve 73 is closed, by the processing of subsequent S42, until the accumulator pressure P _a is the atmospheric pressure, its state is maintained. By such operation of the control valves 86, 91, 73, counter-filter backflow by the hydraulic fluid stored in the pressure accumulator 66 is realized. When the accumulator pressure P _A becomes the atmospheric pressure, at S43, it is closed and the accumulator control valve 86 and the connection passage control valve 91, is opened is pumped path control valve 73, clogging resolving process is completed . After these series of processes, the cancellation process execution flag G is set to 0 in S44, and the process of this subroutine is completed.

  The return flow utilization cancellation processing operation subroutine of S35 is a subroutine whose flowchart is shown in FIG. 11. In the processing of this subroutine, first, in S51, the pumping path control valve 73 is closed, and the connection path control valve 91 and The individual control valve 100 is opened. By such operation of each control valve 73, 91, 100, the working fluid is discharged from the suspension cylinder 10, and counter-filter back flow by the working fluid is realized. Since the vehicle height starts to decrease due to the outflow of the hydraulic fluid from the suspension cylinder 10, in S52, it is determined when the vehicle height detected by the vehicle height sensor 130 becomes the Mid vehicle height. In step S54, the current vehicle height flag F is set to 1. In S54, the individual control valve 100 and the connection path control valve 91 are closed, and the pumping path control valve 73 is opened. After these series of processes, the cancellation process execution flag G is set to 0 in S55, and the process of this subroutine is terminated.

The pump operation use cancellation processing operation subroutine of S36 is a subroutine whose flowchart is shown in FIG. 12. In the processing of this subroutine, first, in S61, the connection path control valve 91 is closed and the pumping path control valve is closed. 73 is opened, the pump device 64 is operated, and the state is maintained until the set time T ₁ (for example, about several seconds) elapses by the process of S62. After the set time T ₁ has elapsed, in S63, the pumping-up path control valve 73 is closed, the connection path control valve 91 is opened, the pump device 64 is stopped, and the subsequent processing in S64 causes the set time T The state is maintained until ₂ (for example, several seconds) elapses. By the operation of the control valves 91 and 73 and the operation of the pump device 64, counter-filter backflow that does not use the hydraulic fluid in the accumulator 66 for accumulating pressure and the suspension cylinder 10 is realized. After the set time T ₂ has elapsed, in S65, the pumping path control valve 73 is opened, and the connection path control valve 91 is closed. The series of processes of S61 to S65 are repeated by the set number of times C ₀ (for example, about 5 times) by the processes of S66 and S67 using the counter C. After the repetitive process, the counter C is reset in S68, the cancellation process execution flag G is set to 0 in S69, and the process of this subroutine is completed.

  After execution of the clogging state elimination processing subroutine, in S10, accumulator pressure recovery processing is executed. In this process, the hydraulic pressure of the accumulator 66 for pressure accumulation detected by the pressure sensor 87 is set to the above-mentioned set standard pressure. When the pressure is lower than the set standard pressure, the pressure accumulation control is performed until the set standard pressure is reached. The valve 86 is opened and the pump device 64 is activated. After the accumulator pressure recovery process is executed, a process for allowing the vehicle height adjustment, specifically, a process for restarting the vehicle height adjustment program is performed in S11. As described above, a series of processes is executed, and one execution of the clogging countermeasure program is completed.

<Functional configuration of ECU>
If the functional configuration of the vehicle height adjustment ECU 120 included in the vehicle height adjustment system is conceptually shown in a block diagram, it is as shown in FIG. This block diagram shows the parts closely related to the claimable invention. Incidentally, the vehicle height adjustment ECU 120 is configured to include a computer constituted by a CPU, ROM, RAM, and the like and a drive circuit. Therefore, each functional unit shown in this figure is conceptually present. Therefore, it can be considered as a part of the vehicle height adjustment ECU 120 that functions by executing the clogging countermeasure program described above.

  The vehicle height adjustment ECU 120 includes a vehicle height adjustment unit 150 as a functional unit that executes processing of a vehicle height adjustment program, that is, a functional unit that executes general vehicle height adjustment. Further, as a functional unit that executes the processes of S2, S5, etc., that is, a functional unit that performs a clogging state recognition process of the filter 67, the clogging state recognition unit 152 is included, and the processes of S9, etc. are executed. The clogging state elimination unit 154 is provided as a functional unit, that is, a functional unit that performs the clogging state elimination processing of the filter 67. More specifically, the clogging state recognition unit 152 is based on the continuous energization guard number-based clogging state recognition unit 156 as a function unit that executes the process of S2, and the hydraulic pressure dependency as a function unit that executes the process of S5. A clogging state recognition unit 158, and the clogging state elimination unit 154 includes an accumulator utilization elimination operation execution unit 160 as a functional unit that executes the process of S32, and a functional unit that executes the process of S35. A feedback flow utilization cancellation operation execution unit 162 and a pump operation utilization cancellation operation execution unit 164 as a functional unit that executes the process of S36 are configured. Further, the vehicle height adjustment ECU 120 functions as a functional unit that executes processing such as S3, that is, as a functional unit that executes the clogging state elimination processing based on the cumulative operating time of the pump device 64. It has a state elimination processing realization unit 166. The vehicle height adjustment ECU 120 controls various types of control valves 73, 86, 90, 91, 100, and 104, and functions as a valve control device.

  In another view of the configuration of the vehicle height adjustment system, the system has a hydraulic pressure source system, and the hydraulic pressure source system includes the hydraulic pressure source device 2 and the vehicle height adjustment ECU 120. It consists of Further, since the vehicle height adjustment system has the function of realizing counter-filter backflow as described above, it can be considered that the vehicle height adjustment system has a counter-filter hydraulic fluid backflow device. It can be considered that the device 2 includes a specific hydraulic fluid passage, a specific control valve, a pump device 64, the clogging state elimination unit 154 of the vehicle height adjustment ECU 120, and the like. Further, since the vehicle height adjustment system has a function of certifying the clogging state of the filter 67, it can be considered that the vehicle height adjustment system has a filter clogging certification device. It can be considered that the clogging state recognition unit 152 is configured.

<Modification regarding hydraulic source device>
FIG. 14 shows a hydraulic pressure source device provided in a vehicle height adjustment system as a modification. This hydraulic pressure source device 2 ′ is obtained by changing a part of the various control valves of the hydraulic pressure source device 2 described above. In view of that, the same reference numerals are used for the same components as those of the previous hydraulic pressure source device 2, and the description thereof is omitted.

  In the hydraulic pressure source device 2 ′, a pumping path connection path switching valve 170 is provided at a connection location between the pumping path 72 and the connection path 89. This pumping path connection path switching valve 170 is an electromagnetic type 2 that can switch between two states, a state in which the pump device 64 and the strainer 68 communicate with each other, and a state in which the connection path 89 and the strainer 68 communicate with each other. The position valve communicates with the pump device 64 and the strainer 68 in the non-excited state, and communicates with the strainer 68 and the connection path 89 in the excited state. Further, a feedback path connection path switching valve 172 is provided at a connection point between the return path 88 and the connection path 89. The return path connection path switching valve 172 is an electromagnetic two-position valve capable of switching between a state in which the hydraulic fluid from the main supply path 74 is introduced into the reservoir 70 and a state in which the hydraulic fluid flows into the connection path 89. In the state, the hydraulic fluid is introduced into the reservoir 70 and can be allowed to flow into the connection path 89 in the excited state. Further, a feedback path supply path switching valve 174 is provided at a connection point between the individual control valve 100 side of the check valve 80 and the feedback path 88 in the main supply path 74. The feedback path supply path switching valve 174 includes a state in which the pump device 64 and the individual control valve 100 communicate with each other, a state in which the feedback path 88 and the individual control valve 100 communicate with each other, a pump apparatus 64 and the feedback path. 88 is an electromagnetic three-position valve capable of switching the state in which it communicates with the pump 88. In the non-excited state, the pump device 64 and the individual control valve 100 are in communication, and in the first excited state, the pump device 64 and the return path 88 and the return path 88 and the individual control valve 100 are communicated in the second excitation state.

  The hydraulic pressure source device 2 ′ can also perform vehicle height increase adjustment, vehicle height decrease adjustment, and vehicle height maintenance adjustment similar to the previous hydraulic pressure source device 2. Moreover, it is possible to realize the counter-filter reverse flow of the three modes described above, that is, to execute the accumulator utilization cancellation processing operation, the feedback flow utilization cancellation processing operation, and the pump operation utilization cancellation processing operation. More specifically, when the accumulator utilization cancellation processing operation is performed, when the pressure accumulation control valve 86 is opened and the individual control valve 100 is closed, the pumping path connection path switching valve 170 and the feedback path connection path switching valve 172 are excited. The return path supply path switching valve 174 is set to the second excitation state. At the time of the return flow utilization elimination processing operation, the pumping path connection path switching valve 170 and the feedback path connection path switching valve 172 are in an excited state in a state where the pressure accumulation control valve 86 is closed and the individual control valve 100 is opened. The return path supply path switching valve 174 is set to the second excitation state. Further, during the pump operation use cancellation processing operation, the pumping path connection path switching valve 170 is in a non-excited state, the feedback path connecting path switching valve 172 is in an excited state, and the feedback path supply path switching valve 174 is in a first excitation state. Thus, the pump device 64 is operated, and after the set time has elapsed, the pump device 64 is stopped and the pumping-up path connection path switching valve 170 is excited.

  In view of the operation of the switching valves 170, 172, and 174 relating to the counter-filter reverse flow, in the hydraulic pressure source device 2 ′, a pump filter shut-off valve device is configured by the pump-up path connection path switching valve 170, and the feedback path connection path switching is performed. The valve 172 constitutes a feedback liquid passage cutoff valve device, the feedback passage supply passage switching valve 174 constitutes a supply fluid passage cutoff valve device, and the three switching valves 170, 172 and 174 constitute a reflux liquid passage. A communication valve device is configured.

It is a figure which shows typically the vehicle height adjustment system containing the hydraulic pressure source system of an Example. It is a graph which shows roughly the hydraulic pressure change state of hydraulic fluid pressure to the elapsed time at the time of vehicle height increase adjustment. It is a graph which shows roughly the relationship between the loading weight of a vehicle for every vehicle height, and hydraulic fluid pressure. It is a figure which shows the flow of the hydraulic fluid in the clogging state elimination process using an accumulator. It is a figure which shows the flow of the hydraulic fluid in the clogging state cancellation | release process using a feedback flow liquid. It is a figure which shows the flow of the hydraulic fluid in a pump action utilization clogging state elimination process. It is a flowchart which shows a clogging countermeasure program. It is a flowchart which shows the hydraulic-pressure based clogging state recognition process subroutine performed in a clogging countermeasure program. It is a flowchart which shows the clogging state elimination process subroutine performed in a clogging countermeasure program. It is a flowchart which shows the accumulator utilization cancellation processing operation subroutine performed in a clogging state cancellation processing subroutine. It is a flowchart which shows the feedback flow utilization cancellation process operation subroutine performed in a clogging state cancellation process subroutine. It is a flowchart which shows the pump operation utilization cancellation process operation subroutine performed in a clogging state cancellation process subroutine. It is a block diagram which shows notionally the functional structure of the electronic control unit which is a control apparatus of a vehicle height adjustment system. It is a figure which shows notionally the hydraulic pressure source apparatus at the time of replacing each cutoff / communication valve of a hydraulic pressure source apparatus with each switching valve.

Explanation of symbols

2, 2 ′: Vehicle hydraulic pressure source device 4: Vehicle height adjusting device (vehicle hydraulic pressure operating device) 10: Suspension cylinder (actuator) 40: Individual supply passage (supply fluid passage) 64: Pump device 66: Accumulator for pressure accumulation (Accumulator) 67: Filter 68: Strainer 70: Reservoir 72: Pumping passage (pumping fluid passage) 73: Pumping passage control valve (pump filter shutoff valve device) 74: Main supply passage (supply fluid passage) 80: Check valve (Reverse flow prohibition valve device) 88: Return path (return liquid passage, reflux liquid passage) 89: Connection path (connection liquid passage, reflux liquid passage) 90: Return path control valve (feedback fluid path shut-off valve device) 91: Connection path Control valve (return liquid passage communication valve device) 100: Individual control valve (supply liquid passage shut-off valve device) 120: Inter-vehicle distance adjustment electronic control unit (valve control device) 152: Filter clogging state recognition unit (filter 154: Filter clogging state elimination unit 170: Pumping path connection path switching valve (pump filter shutoff valve device, reflux liquid passage communication valve apparatus) 172: Feedback path connection path switching valve (feedback fluid path shutoff valve device) , Reflux fluid passage communication valve device) 174: Return path supply passage switching valve (Supply fluid passage cutoff valve device, reflux fluid passage communication valve device)

Claims (6)

A reservoir for storing the working fluid, a pump device for discharging the working fluid pumped from the reservoir, a pumping fluid passage connecting the reservoir and the pump device, and a working fluid discharged from the pump device as the working fluid A vehicle hydraulic pressure source system comprising: a supply fluid passage that is supplied to an on-vehicle fluid pressure actuation device that is actuated by; and a filter that is provided in the middle of the pumping fluid passage,
A vehicle hydraulic pressure source system including a counter-filter working fluid backflow device that realizes counter-filter backflow, which is a reverse flow of the working fluid with respect to the filter, by causing the working fluid to flow back through the pumping fluid passage. The anti-filter hydraulic fluid backflow device is
A reflux liquid passage connecting the portion between the filter and the pump device in the pumped liquid passage and the supply liquid passage; a reflux liquid passage communication valve device that operates to connect the reflux liquid passage; And a valve control device for controlling the operation of the liquid passage communication valve device, and the counter-filter by the working fluid flowing from the supply liquid passage through the reflux liquid passage into the pumping liquid passage by communicating the reflux liquid passage The vehicle hydraulic pressure source system according to claim 1, which realizes a reverse flow. The vehicle hydraulic pressure source system is a liquid passage that branches off from the supply liquid passage and reaches the reservoir, and returns the hydraulic fluid that returns from the in-vehicle hydraulic actuator through the supply liquid passage to the reservoir. With a passage,
The anti-filter hydraulic fluid backflow device is
By providing a connection liquid passage that connects a location in the middle of the return liquid passage and a location between the filter and the pump device in the pumping liquid passage, the return liquid passage is formed by the connection liquid passage and the return liquid passage. A feedback fluid passage shut-off valve device configured to be configured and operated to shut off a portion in the middle of the feedback fluid passage and the reservoir;
The vehicle hydraulic pressure source system according to claim 2, wherein the valve control device controls the feedback fluid passage cutoff valve device to operate when the counter-filter backflow is realized.   The vehicle hydraulic pressure source system is provided in the supply liquid passage with the counter-filter reverse flow by the hydraulic fluid returning from the in-vehicle hydraulic pressure operating device through the supply liquid passage, and the vehicle hydraulic pressure source system is provided in the supply liquid passage. 4. The vehicle hydraulic pressure source system according to claim 2, wherein in the case of including an accumulator that stores hydraulic fluid, at least one of the counter-filter back flow by the hydraulic fluid from the accumulator is realized. 5. The anti-filter hydraulic fluid backflow device is
A supply liquid passage shut-off valve device that shuts off the connection between the supply liquid passage and the reflux liquid passage and the in-vehicle hydraulic pressure operating device by being actuated, and the valve control device shuts off the supply liquid passage; The control device according to claim 2 or 3, wherein the valve device is controlled so as to operate in an operating state of the pump device, and then the counter-filter reverse flow is realized by communicating the reflux liquid passage. Vehicle hydraulic pressure source system. The vehicle hydraulic pressure source system includes a filter clogging certifying device that certifies that the filter is clogged, and the anti-filter hydraulic fluid backflow device is based on the certification by the filter clogging certifying device, The counter-filter backflow is realized,
The filter clogging recognition device includes a number of times of continuous operation exceeding a set time of the pump device, and a hydraulic pressure change state of hydraulic fluid supplied to the on-vehicle hydraulic pressure device when the pump device is operated. The vehicle hydraulic pressure source system according to any one of claims 1 to 5, wherein the filter is certified to be clogged based on at least one of them.

Images