JP4483790B2 - Regulating valve - Google Patents

Description

  The present invention relates to a regulating valve that regulates a discharge pressure of a fluid by a pump.

[Conventional technology]
Conventionally, a regulator valve supplies high-pressure fuel to an engine together with, for example, a low-pressure pump that sucks and discharges fuel from a fuel tank, and a high-pressure pump that sucks and discharges fuel discharged from a low-pressure pump. The supply pump is configured to be assembled in order to regulate the fuel discharge pressure by the low pressure pump.

  As shown in FIG. 4, the conventional regulating valve 100 includes a valve body 101 that opens and closes between a discharge side of a low-pressure pump (not shown) and a suction side of the low-pressure pump, and the valve body 101 is closed in the valve closing direction. And a valve body 103 that houses the restoring spring 102, a bush 104 that serves as a stopper of the valve body 101, and a plug 105 that serves as a mounting seat for the restoring spring 102.

  When the fuel discharge pressure by the low-pressure pump exceeds the regulation value, the valve body 101 is biased by the discharge pressure and displaced in the valve opening direction, thereby communicating between the discharge side of the low-pressure pump and the suction side of the low-pressure pump. .

  The restoring spring 102 is attached with elastic stress applied so as to urge the valve body 101 in the valve closing direction. The restoring spring 102 urges the valve body 101 in the valve closing direction by the elastic stress (setting force) applied at the time of mounting, and abuts the bush 104. This set force is determined according to the regulation value of the discharge pressure. When the discharge pressure becomes equal to or higher than the regulation value, the restoring spring 102 is compressed by the discharge pressure and stores an elastic stress stronger than the set force.

  The valve body 103 movably accommodates the valve body 101 and has an outlet 106 that opens to the discharge side of the low-pressure pump through the suction side of the low-pressure pump and opens in the valve opening direction of the valve body 101. . A bush 104 is attached to the front end of the valve body 103, and a plug 105 is attached to the rear end. Here, the bush 104 is provided in a cylindrical shape and forms an inlet 107 that leads to the discharge side of the low-pressure pump. The inflow port 107 is closed with respect to the outflow port 106 by the valve body 101 biased by the setting force of the restoring spring 102. When the discharge pressure becomes equal to or higher than the regulation value, the valve body 101 is displaced in the valve opening direction, and the inlet 107 is opened with respect to the outlet 106.

  With the above configuration, when the fuel discharge pressure by the low pressure pump exceeds the regulation value, the regulating valve 100 displaces the valve body 101 in the valve opening direction, and discharges the low pressure pump via the inlet 107 and the outlet 106. And the suction side of the low pressure pump. Thus, the regulating valve 100 regulates the discharge pressure by allowing fuel to escape from the discharge side of the low-pressure pump to the suction side of the low-pressure pump (see, for example, Patent Document 1).

[Problems with conventional technology]
However, when the pressure on the suction side of the low-pressure pump (suction pressure) becomes small for some reason, the discharge pressure pulsates. When the pulsation width is large, the restoring spring 102 is instantaneously greatly compressed and accumulates extremely large elastic stress. For this reason, there is a possibility that the restoring spring 102 is damaged or the plug 105 is pulled out to the rear end side.
Japanese Patent Laid-Open No. 2005-98286

  The present invention has been made in order to solve the above-described problems. The purpose of the present invention is to prevent the restoring spring from being damaged or the plug to be plugged even if a large pulsation occurs in the discharge pressure to be regulated by the regulating valve. It is to reduce the possibility of slipping out.

[Means of Claim 1]
According to the first aspect of the present invention, when the fluid discharge pressure by the pump exceeds a regulation value, the regulator valve is urged by the discharge pressure to displace in the valve opening direction, and between the pump discharge side and the pump suction side. A valve body that communicates with the valve body, and is attached with elastic stress applied so as to urge the valve body in the valve closing direction, and when the discharge pressure exceeds the regulation value, it is compressed by the discharge pressure and is stronger than when it is installed. A restoring spring that stores stress, a valve body that is movably accommodated, a first outlet that is connected to the suction side of the pump and opened to the discharge side of the pump by displacement in the valve opening direction; and A valve body having a second outlet that communicates with the suction side of the pump separately from the first outlet, and is attached to the valve body and closes the second outlet with respect to the discharge side of the pump and contacts the valve body The valve body is displaced in the valve opening direction. And a second outlet closure member abutting the valve body is released.

  The regulator valve communicates between the pump discharge side and the pump suction side via the first outlet when the fluid discharge pressure by the pump exceeds a regulation value, and the pump discharge side from the pump discharge side The fluid is allowed to escape to the suction side to regulate the discharge pressure. When the discharge pressure pulsates and reaches the upper limit value higher than the regulation value, the valve body accelerated by the elastic stress according to the upper limit value is closed to the second outlet. And a second outlet closing member is displaced to open the second outlet with respect to the discharge side of the pump, and the discharge side of the pump and the suction side of the pump are connected via the second outlet. Communicate between them.

  That is, in the present invention, the upper limit value for the discharge pressure is set as a reference for regulating the elastic stress that causes the breakage of the restoring spring and the plug coming out. That is, the higher the discharge pressure, the stronger the elastic stress stored in the restoration spring, and the higher the risk that the restoration spring will be damaged or the plug will come out. Therefore, the upper limit value is set to a value lower than the discharge pressure at which the restoring spring is broken or the plug is pulled out and higher than the regulation value.

  Then, before the breakage of the restoring spring or the plug comes out, the valve body accelerated by the elastic stress is brought into contact with the second outlet closing member to displace the second outlet closing member, and the second outlet Is opened to the discharge side of the pump. That is, the second outlet closing member is lightly attached to the valve body so that when the valve body is accelerated by an elastic stress of a certain level or more, the second outlet closing member can be brought into contact with the accelerated valve body and displaced. It is press-fitted. For this reason, once the second outlet closing member cannot be returned to the pre-displacement state once displaced, the second outlet is always open to the discharge side of the pump.

  As a result, the pulsation of the discharge pressure can be suppressed by allowing the fuel to always escape from the second outlet before the restoration spring is damaged or the plug is pulled out. For this reason, even if a large pulsation occurs in the discharge pressure to be regulated by the regulating valve, it is possible to reduce the possibility that the restoring spring is damaged or the plug is pulled out.

[Means of claim 2]
According to the regulator valve of claim 2, the second outlet closing member has a fluid passage, and the fluid passage is an inflow side opening that always communicates with the discharge side of the pump, and an outflow that is closed by the valve body. A side opening is formed, and the outflow side opening is opened to the first outlet when the valve element is displaced in the valve opening direction.
This means shows one form of the second outlet closing member.

[Means of claim 3]
According to a third aspect of the present invention, the valve body accelerated by the elastic stress corresponding to the upper limit value is in contact with the second outlet closing member between the regulated valve and the assembly to which the regulated valve is assembled. When this is done, the second outlet closing member is displaced to form a space to escape.
According to this, the space which the 2nd outflow port closing member displaces and escapes can be formed easily.

[Means of claim 4]
According to a fourth aspect of the present invention, there is provided a supply valve for supplying high-pressure fuel to the engine, together with a high-pressure pump that discharges the fuel at a high pressure and a low-pressure pump that sucks the fuel in the fuel tank and discharges the fuel to the high-pressure pump. When the discharge pressure of the fuel by the low-pressure pump exceeds the regulation value, the fuel is allowed to escape from the discharge side of the low-pressure pump to the suction side of the low-pressure pump to regulate the discharge pressure.
This means shows one application example of the regulating valve.

[Means of claim 5]
The regulator valve according to claim 5 has a high-pressure pump that discharges the fuel after increasing the pressure, and a low-pressure pump that sucks the fuel in the fuel tank and discharges it to the high-pressure pump, and supplies the high-pressure fuel to the engine. When the pump is used as an assembly and the discharge pressure of the fuel from the low-pressure pump exceeds the regulation value, the fuel is released from the discharge side of the low-pressure pump to the suction side of the low-pressure pump to regulate the discharge pressure.
This means shows one application example of the regulating valve.

  When the fluid discharge pressure by the pump exceeds the regulation value, the regulator valve of the best mode 1 is biased by the discharge pressure and displaced in the valve opening direction, and between the pump discharge side and the pump suction side. The valve body to be communicated and attached with elastic stress so as to urge the valve body in the valve closing direction, and when the discharge pressure exceeds the regulation value, it is compressed by the discharge pressure and stronger than when it is installed A first return outlet that is movably accommodated in the valve body and is opened to the discharge side of the pump by displacement in the valve opening direction through the suction side of the pump, and A valve body having a second outlet that communicates with the suction side of the pump separately from the one outlet, and is attached to the valve body to close the second outlet with respect to the discharge side of the pump and is in contact with the valve body When the valve body is displaced in the valve opening direction And a second outlet closure member abutting the body is released.

  The regulator valve communicates between the pump discharge side and the pump suction side via the first outlet when the fluid discharge pressure by the pump exceeds a regulation value, and the pump discharge side from the pump discharge side The fluid is allowed to escape to the suction side to regulate the discharge pressure. When the discharge pressure pulsates and reaches the upper limit value higher than the regulation value, the valve body accelerated by the elastic stress according to the upper limit value is closed to the second outlet. And a second outlet closing member is displaced to open the second outlet with respect to the discharge side of the pump, and the discharge side of the pump and the suction side of the pump are connected via the second outlet. Communicate between them.

  In addition, according to this regulated valve, the second outlet closing member has a fluid passage, and the fluid passage is always connected to the discharge side of the pump, and the outlet side opening is closed by the valve body. When the valve element is displaced in the valve opening direction, the outflow side opening is opened with respect to the first outlet.

  In addition, when the valve body accelerated by the elastic stress corresponding to the upper limit value is in contact with the second outlet closing member between the regulated valve and the assembled body to which the regulated valve is assembled, The second outlet closing member is displaced to form a space to escape.

  In addition, this regulating valve constitutes a supply pump that supplies high-pressure fuel to the engine, together with a high-pressure pump that discharges fuel by increasing its pressure, and a low-pressure pump that sucks fuel from the fuel tank and discharges it to the high-pressure pump. When the discharge pressure of the fuel by the low-pressure pump exceeds the regulation value, the fuel is released from the discharge side of the low-pressure pump to the suction side of the low-pressure pump to regulate the discharge pressure.

  In other words, this regulating valve has a high-pressure pump that discharges the fuel at a high pressure and a low-pressure pump that sucks the fuel in the fuel tank and discharges it to the high-pressure pump, and a supply pump that supplies high-pressure fuel to the engine. When the fuel discharge pressure by the low-pressure pump becomes equal to or higher than the regulation value, the assembly is made to release the fuel from the discharge side of the low-pressure pump to the suction side of the low-pressure pump, thereby regulating the discharge pressure.

[Configuration of Example 1]
The configuration of the regulating valve 1 according to the first embodiment will be described with reference to FIGS. 1 to 3.
For example, as shown in FIG. 1, the regulator valve 1 includes a high-pressure pump 2 that discharges fuel by increasing its pressure, a low-pressure pump 4 that sucks fuel from the fuel tank 3 and discharges it to the high-pressure pump 2, and a low-pressure pump 4. A supply pump 6 that supplies high-pressure fuel to an engine (not shown) is configured together with an intake metering valve 5 and the like that meter fuel supplied to the high-pressure pump 2. That is, the assembly to which the regulated valve 1 is assembled is the supply pump 6.

  The supply pump 6 includes, for example, an injector 7 that injects fuel into the cylinder of the engine, a common rail 8 that accumulates fuel supplied from the supply pump 6 in a high pressure state and distributes the fuel to the injector 7, the supply pump 6 and the injector An accumulator fuel injection device 9 is configured together with an electronic control device (ECU: not shown) for controlling the drive of the motor 7. That is, this fuel injection device 9 is provided with the regulating valve 1 in the supply pump 6.

  Here, the high-pressure pump 2 constituting the supply pump 6 is housed in a body 13 so as to reciprocate, a plunger 15 forming a fuel pressurizing chamber 14, a drive shaft 16 driven to rotate by the engine, and a drive shaft 16 The cam mechanism 17 that converts the rotational motion of the valve into a linear reciprocating motion and transmits it to the plunger 15 and the check valve 18 that prevents the fuel in the pressurizing chamber 14 from flowing back upstream (that is, toward the intake metering valve 5). The check valve 19 is configured to prevent fuel downstream from the pressurizing chamber 14 (that is, the common rail 8) from flowing back into the pressurizing chamber 14.

  The high pressure pump 2 linearly reciprocates the plunger 15 in synchronism with the rotation of the drive shaft 16 and expands and contracts the pressurizing chamber 14, thereby sucking fuel into the pressurizing chamber 14 and increasing the pressure of the sucked fuel. And discharged from the pressurizing chamber 14.

The low-pressure pump 4 is, for example, a known trochoid pump that is attached to one end of the drive shaft 16 and is driven to rotate by an engine.
The intake metering valve 5 has a solenoid coil 21 that is energized in accordance with a command from the ECU. The intake metering valve 5 supplies the high pressure pump 2 from the low pressure pump 4 by adjusting the opening degree of the fuel flow path 22 from the low pressure pump 4 to the high pressure pump 2 according to the energization amount of the solenoid coil 21. Meter the fuel to be used.

  As shown in FIG. 2, the regulator valve 1 is configured to open and close between the discharge side of the low-pressure pump 4 and the suction side of the low-pressure pump 4, and to bias the valve body 24 in the valve closing direction. A restoring spring 25 to which elastic stress is applied, a valve body 26 that movably accommodates the valve body 24, a bush 27 that serves as a stopper of the valve body 24, and a plug 28 that serves as a mounting seat for the restoring spring 25 Is provided.

  The valve body 24 has a restoring spring 25 attached to the rear end thereof and is urged in the valve closing direction by elastic stress. When the fuel discharge pressure by the low-pressure pump 4 exceeds the regulation value, the valve body 24 is biased by the discharge pressure and displaced in the valve opening direction, and the discharge side of the low-pressure pump 4 and the suction side of the low-pressure pump 4 Communicate between the two.

  The restoring spring 25 urges the valve body 24 in the valve closing direction to abut against the bush 27 by an elastic stress (referred to as a set force) applied at the time of mounting. This set force is determined according to the regulation value of the discharge pressure, and the restoring spring 25 is compressed by the discharge pressure when the discharge pressure exceeds the regulation value, and stores an elastic stress stronger than the set force.

  The valve body 26 movably accommodates the valve body 24 and communicates with the suction side of the low-pressure pump 4 and is opened to the discharge side of the low-pressure pump 4 by the displacement of the valve body 24 in the valve opening direction. In addition to the outlet 31 and the first outlet 31, a second outlet 32 that leads to the suction side of the low-pressure pump 4 is provided. Further, a bush 27 is attached to the front end of the valve body 26, and a plug 28 is attached to the rear end. The second outlet 32 is provided on the front end side of the first outlet 31 and is closed by the bush 27.

  The bush 27 is attached to the tip of the valve body 26 and forms a second outlet closing member that closes the second outlet 32 with respect to the discharge side of the low-pressure pump 4. Further, the bush 27 is brought into contact with the valve body 24 at the rear end, and when the valve body 24 is displaced in the valve opening direction, the contact of the valve body 24 is released. The bush 27 is provided in a cylindrical shape to form a fuel passage 34, and the fuel passage 34 opens at both the front end and the rear end.

  The opening at the front end forms an inflow side opening 35 that always communicates with the discharge side of the low-pressure pump 4, and the opening at the rear end forms an outflow side opening 36 that is closed by the valve body 24. And the outflow side opening part 36 is open | released with respect to the 1st outflow port 31, if discharge pressure becomes more than regulation value and the valve body 24 displaces to a valve opening direction. As a result, the fuel on the discharge side of the low-pressure pump 4 is released to the suction side of the low-pressure pump 4 via the first outlet 31. When the discharge pressure becomes less than the regulation value and the valve body 24 is displaced in the valve closing direction, the outflow side opening 36 is closed with respect to the first outlet 31, and the fuel on the discharge side of the low pressure pump 4 is the low pressure pump 4. Will not be missed by the inhalation side.

  Further, the bush 27 functions as a safety member for preventing the restoration spring 25 from being damaged, the plug 28 being pulled out, and the like when the elastic stress of the restoration spring 25 becomes excessive due to the pulsation of the discharge pressure. That is, in the regulator valve 1, an upper limit value for the discharge pressure is set as a reference for regulating the elastic stress that causes the restoring spring 25 to be damaged or the plug 28 to come out. That is, as the discharge pressure becomes higher, the elastic stress stored in the restoring spring 25 becomes stronger, and the possibility that the restoring spring 25 is damaged or the plug 28 is pulled out increases. Therefore, the upper limit value is set to a value lower than the discharge pressure at which the restoring spring 25 is broken or the plug 28 is pulled out, and higher than the regulation value.

  When the discharge pressure pulsates and exceeds the upper limit value, the valve body 24 accelerated by the elastic stress contacts the bush 27 and displaces the bush 27. That is, a space 39 is formed in advance between the bush 27 and the body 38 of the supply pump 6 so that the bush 27 is displaced. That is, when the regulated valve 1 is assembled to the supply pump 6 as an assembly, a space 39 is formed between the regulated valve 1 and the body 38 so that the bush 27 is displaced and escapes. As a result, as shown in FIG. 3, the second outlet 32 is opened to the discharge side of the low-pressure pump 4, and the fuel on the discharge side of the low-pressure pump 4 passes through the second outlet 32. Escaped to the inhalation side.

  The bush 27 is lightly press-fitted into the valve body 26 so as to be displaced by being brought into contact with the valve body 24 accelerated by elastic stress. And the holding force with which the valve body 26 holds the bush 27 is generated by light press fitting, and the strength of this holding force is determined according to the upper limit value of the discharge pressure. Further, since the bush 27 is lightly press-fitted into the valve body 26, once it is displaced, it cannot return to the state before the displacement. For this reason, once the bush 27 is displaced, the second outlet 32 is always opened to the discharge side of the low-pressure pump 4.

[Effect of Example 1]
According to the regulating valve 1 of the first embodiment, when the discharge pressure pulsates and reaches the upper limit value higher than the regulation value, the valve body 24 accelerated by the elastic stress corresponding to the upper limit value is applied to the bush 27. The bush 27 is displaced in contact therewith.
As a result, the second outlet 32 is opened to the discharge side of the low-pressure pump 4, and the discharge side of the low-pressure pump 4 and the suction side of the low-pressure pump 4 communicate with each other via the second outlet 32. Here, the upper limit value is set to a value lower than the discharge pressure at which the restoring spring 25 is damaged or the plug 28 is pulled out, and higher than the regulation value. For this reason, it is possible to always allow the fuel to escape from the second outlet 32 before the restoring spring 25 is broken or the plug 28 is pulled out. As a result, even if a large pulsation occurs in the discharge pressure to be regulated by the regulating valve 1, it is possible to reduce the possibility that the restoring spring 25 is broken or the plug 28 is pulled out.

Further, when the valve body 24 accelerated by the elastic stress corresponding to the upper limit value is brought into contact with the bush 27 between the regulator valve 1 and the body 38, the regulator valve 1 is displaced. An escape space 39 is formed.
Thereby, the space 39 in which the bush 27 is displaced and escapes can be easily formed.

[Modification]
The second outlet closing member of the first embodiment is the bush 27 that forms the stopper of the valve body 24. However, a member different from the bush 27 is lightly press-fitted to the rear end side of the bush 27 to close the second outlet. It may be used as a member.

It is sectional drawing which shows the structure of a supply pump (Example 1). It is sectional drawing which shows the structure of a regulating valve (Example 1). It is sectional drawing which shows the regulating valve after bush displacement (Example 1). It is sectional drawing which shows the structure of a regulating valve (conventional example).

Explanation of symbols

1 Regulating valve 2 High pressure pump 3 Fuel tank 4 Low pressure pump (pump)
6 Supply pump (attachment)
24 Valve body 25 Restoring spring 26 Valve body 27 Bush (second outlet closing member)
31 First outlet 32 Second outlet 34 Fuel passage (fluid passage)
35 Inlet side opening 36 Outlet side opening 39 Space

Claims (5)

When the fluid discharge pressure by the pump is equal to or higher than a regulation value, the valve body is displaced by the discharge pressure and displaced in the valve opening direction, and communicates between the discharge side of the pump and the suction side of the pump;
The valve body is mounted with elastic stress applied so as to urge the valve body in the valve closing direction, and when the discharge pressure exceeds the regulation value, the valve body is compressed by the discharge pressure and stores stronger elastic stress than that at the time of mounting. A restoring spring,
A first outlet that accommodates the valve body movably and opens to the discharge side of the pump by displacement in the valve opening direction through the suction side of the pump; A valve body having a second outlet leading to the suction side of the pump separately from the outlet;
Attached to the valve body closes the second outlet with respect to the discharge side of the pump, is brought into contact with the valve body, and when the valve body is displaced in the valve opening direction, the valve body comes into contact. A second outlet closing member to be released,
When the discharge pressure becomes equal to or higher than the regulation value, fluid is communicated between the discharge side of the pump and the suction side of the pump via the first outlet, and fluid is transferred from the discharge side of the pump to the suction side of the pump. To regulate the discharge pressure,
When the discharge pressure pulsates and reaches an upper limit value higher than the regulation value, the valve body accelerated by the elastic stress corresponding to the upper limit value is brought into contact with the second outlet closing member, and A second outlet closing member is displaced to open the second outlet with respect to the discharge side of the pump, and between the discharge side of the pump and the suction side of the pump via the second outlet. Regulating valve characterized by communicating. The regulated valve according to claim 1,
The second outlet closing member has a fluid passage;
This fluid passage forms an inflow side opening that always leads to the discharge side of the pump, and an outflow side opening that is closed by the valve body,
The outflow side opening is opened with respect to the first outlet when the valve body is displaced in the valve opening direction. The regulated valve according to claim 2,
When the valve body accelerated by the elastic stress according to the upper limit value is in contact with the second outlet closing member between the assembled body to which the regulating valve is assembled, the second flow A regulating valve, wherein the outlet closing member is displaced to form a space for escape. The regulated valve according to claim 1 or 2,
A supply pump for supplying high-pressure fuel to the engine together with a high-pressure pump that discharges the fuel at a high pressure and a low-pressure pump that sucks fuel from the fuel tank and discharges it to the high-pressure pump,
When the fuel discharge pressure by the low-pressure pump becomes equal to or higher than the regulation value, the regulation valve controls the discharge pressure by allowing fuel to escape from the discharge side of the low-pressure pump to the suction side of the low-pressure pump. The regulated valve according to claim 3,
A high-pressure pump that discharges fuel at a high pressure, and a low-pressure pump that sucks fuel from a fuel tank and discharges the fuel to the high-pressure pump, and a supply pump that supplies high-pressure fuel to the engine is the assembly.
When the fuel discharge pressure by the low-pressure pump becomes equal to or higher than the regulation value, the regulation valve controls the discharge pressure by allowing fuel to escape from the discharge side of the low-pressure pump to the suction side of the low-pressure pump.

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