Negative pressure adjustment valve

Abstract

An object of the present invention is to provide a negative pressure regulating valve in which the behavior of the plunger is stable. [Solution] A negative pressure regulating valve comprising a first passage communicating with a negative pressure pump, a second passage communicating with a negative pressure actuator, a third passage communicating with the atmosphere, and a switching mechanism that switches between communication and blocking of the first, second, and third passages, wherein the switching mechanism includes a plunger that moves to a first and second position by an electromagnetic actuator, a valve body held by the plunger, and a blocking member that is held by the plunger and abuts against the valve body.

Description

[Technical Field]

[0001] The present invention relates to a negative pressure regulating valve. [Background technology]

[0002] There is a negative pressure regulating valve that includes a first passage that communicates with a negative pressure pump, a second passage that communicates with a negative pressure actuator, a third passage that communicates with the atmosphere, and a switching mechanism that switches between communication and blocking of the first, second, and third passages (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-076900 A Summary of the Invention [Problem to be solved by the invention]

[0004] The switching mechanism may include a plunger that is moved by an electromagnetic actuator and a valve body held by the plunger. When the plunger moves from a position where the valve body closes the first passage to a position where the valve body is separated from the first passage, the valve body opens the first passage, connecting the first passage to the second passage. When the valve body opens the first passage in this way, the behavior of the plunger may become unstable.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a negative pressure regulating valve in which the behavior of the plunger is stable. [Means for solving the problem]

[0006] The above object is to provide a pressure regulator comprising a first passage communicating with a negative pressure pump, a second passage communicating with a negative pressure actuator, a third passage communicating with the atmosphere, and a switching mechanism for switching between communication and blocking of the first, second, and third passages, wherein the switching mechanism includes a plunger that is moved to a first and second position by an electromagnetic actuator, a valve body held by the plunger, and a blocking member that is held by the plunger and abuts against the valve body, and when the plunger is at the first position, the valve body opens the first passage, connecting the first passage and the second passage, and the valve body and the blocking member block the third passage from the first and second passages, and when the plunger is at the second position, the valve body closes the first passage, blocking the first passage from the second passage, and the valve body and the blocking member a blocking member blocks the third passage from the first and second passages; when the plunger is at the first position and negative pressure is created in the first and second passages by the negative pressure pump, the plunger moves to the second position, and negative pressure acts on the valve body to keep the first passage closed; the valve body opens the first passage when the plunger moves to the first position against the negative pressure acting on the valve body; the blocking member has an atmosphere allowing hole that allows air to be introduced from the third passage to the second passage so that the negative pressure in the second passage is reduced when the plunger is at the second position, and the inner diameter of the atmosphere allowing hole is set to a size that stabilizes the behavior of the plunger when it moves from the second position to the first position. [Effects of the Invention]

[0007] According to the present invention, a negative pressure regulating valve with a stable plunger behavior can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] 1A and 1B are schematic diagrams of a negative pressure adjustment valve. [Figure 2] FIG. 2 is a schematic diagram of the negative pressure adjusting valve. [Figure 3] FIG. 3 is a graph showing the relationship between the negative pressure consumption rate and the inner diameter of the air-permitting hole. DETAILED DESCRIPTION OF THE INVENTION

[0009] [General configuration of negative pressure adjustment valve] 1A, 1B, and 2 are schematic diagrams of an electromagnetic negative pressure regulating valve (electric vacuum regulating valve) 1. In this embodiment, the negative pressure regulating valve 1 mounted on a vehicle will be described as an example. The negative pressure regulating valve 1 is controlled by an ECU (Electronic Control Unit) mounted on the vehicle. The ECU controls the operation of the engine mounted on the vehicle.

[0010] The vacuum regulating valve 1 includes a housing 10, a vacuum supply pipe 20 provided within the housing 10, an electromagnetic actuator 30, a plunger 32, a valve element 36, and a shutoff sleeve 40. The plunger 32, the valve element 36, and the shutoff sleeve 40 are an example of a switching mechanism. A first passage 11, a second passage 12, a third passage 13, a communication chamber 14, and an atmosphere introduction chamber 15 are formed within the housing 10. The first passage 11 is in communication with a vacuum pump 101. A base end of a vacuum supply pipe 20 is inserted into the first passage 11, and a tip end of the vacuum supply pipe 20 protrudes from the first passage 11 into the communication chamber 14. The vacuum pump 101 is controlled by the ECU described above, but is not limited thereto, and may be driven by, for example, an engine camshaft.

[0011] The second passage 12 is connected to a vacuum actuator 102. The vacuum actuator 102 is a diaphragm-type vacuum actuator that drives a wastegate valve. The wastegate valve opens and closes a passage that bypasses a turbine of a supercharger that is arranged in an exhaust passage of an engine mounted on a vehicle.

[0012] The first passage 11 and the second passage 12 communicate with each other via a communication chamber 14. A cutoff sleeve 40 is housed in the communication chamber 14 so as to be horizontally movable. The cutoff sleeve 40 is fixed to the tip of the plunger 32. The plunger 32 extends in the axial direction A, and is housed in the housing 10 so as to be reciprocable within a predetermined range along the axial direction A by the electromagnetic actuator 30. Therefore, the cutoff sleeve 40 can reciprocate within a predetermined range along the axial direction A together with the plunger 32.

[0013] The third passage 13 communicates with the atmosphere. The third passage 13 communicates with the atmosphere introduction chamber 15. The atmosphere introduction chamber 15 is a cylindrical space formed around the blocking sleeve 40.

[0014] A recess 34 is formed at the tip of the plunger 32. A valve body 36 is held in the recess 34. The valve body 36 is elastically deformable within a predetermined range in the axial direction A while being held in the recess 34.

[0015] The shutoff sleeve 40 includes a cylindrical portion 42, a flange portion 44, and a cylindrical seal portion 46. The base end of the cylindrical portion 42 is fixed to the plunger 32. The flange portion 44 is flange-shaped and extends radially inward from the cylindrical portion 42. The cylindrical seal portion 46 extends cylindrically from the flange portion 44 toward the plunger 32. The inner diameter of the cylindrical seal portion 46 is larger than the outer diameter of the negative pressure supply pipe 20, and the tip of the negative pressure supply pipe 20 is located within the cylindrical seal portion 46 and faces the valve element 36. The outer diameter of the cylindrical seal portion 46 is smaller than the outer diameter of the valve element 36, and the tip of the cylindrical seal portion 46 abuts against the tip of the valve element 36. A plurality of atmospheric air introduction holes 47 are provided at predetermined intervals in the circumferential direction on the tip side of the flange portion 44 of the cylindrical portion 42. An atmospheric air permissive hole 45, described in detail below, is formed in the flange portion 44 so as to penetrate the flange portion 44 in the axial direction A. The blocking sleeve 40 is an example of a blocking member.

[0016] 1A, the tip of the negative pressure supply pipe 20 is separated from the valve body 36, and the tip of the cylindrical seal portion 46 abuts against the tip of the valve body 36. Therefore, the first passage 11 and the second passage 12 communicate with each other via the communication chamber 14, and the third passage 13 is blocked from the first passage 11 and the second passage 12. The position of the plunger 32 in FIG. 1A is referred to as the first position. In the state of FIG. 1A, negative pressure is supplied from the negative pressure pump 101 to the negative pressure actuator 102 via the first passage 11, the communication chamber 14, and the second passage 12.

[0017] When the plunger 32 and the blocking sleeve 40 move toward the negative pressure supply pipe 20 from the state shown in FIG. 1A, the tip of the negative pressure supply pipe 20 abuts against the tip of the valve element 36, as shown in FIG. 1B. This blocks the first passage 11 from the second passage 12. That is, the first passage 11, the second passage 12, and the third passage 13 are blocked from each other. The position of the plunger 32 in FIG. 1B is referred to as the second position. When the plunger 32 moves from the first position to the second position, a negative pressure is maintained within the first passage 11, the communication chamber 14, and the second passage 12. The negative pressure within the first passage 11, the communication chamber 14, and the second passage 12 acts on the valve element 36 in a direction that attracts the valve element 36 to the tip of the negative pressure supply pipe 20, i.e., in a direction that causes the valve element 36 to close the first passage 11. As will be described in detail later, the atmosphere is introduced from the third passage 13 into the second passage 12 through the atmosphere permissive hole 45, and the negative pressure in the second passage 12 gradually decreases.

[0018] 1B, the valve element 36 is compressed by the vacuum supply pipe 20, as shown in FIG. 2. This causes the tip of the valve element 36 to move away from the tip of the cylindrical seal portion 46. This allows the third passage 13 and the second passage 12 to communicate with each other via the plurality of atmosphere introduction holes 47, the gap between the valve element 36 and the cylindrical seal portion 46, and the gap between the inside of the cylindrical seal portion 46 and the outside of the vacuum supply pipe 20. In the state of FIG. 1B, the atmosphere is supplied to the second passage 12 via the third passage 13, and the vacuum supplied to the vacuum actuator 102 decreases.

[0019] 1A while the negative pressure in the second passage 12 is large in the state of FIG. 1B, a large force is required on the plunger 32 to separate the valve element 36 from the tip of the negative pressure supply pipe 20. Furthermore, when the tip of the negative pressure supply pipe 20 separates from the tip of the valve element 36, the force acting on the valve element 36 in the valve closing direction due to the negative pressure suddenly decreases, and the behavior of the plunger 32 may become unstable.

[0020] Therefore, an atmosphere allowable hole 45 is formed in the flange portion 44 of the shutoff sleeve 40. In the state shown in Fig. 1B, the atmosphere allowable hole 45 allows the introduction of atmosphere from the third passage 13 to the second passage 12. In detail, the atmosphere is introduced from the third passage 13 to the communication chamber 14 and the second passage 12 via the atmosphere introduction chamber 15, the atmosphere introduction hole 47, and the atmosphere allowable hole 45. Here, the inner diameter of the atmosphere allowable hole 45 is set to a predetermined lower limit value or more.

[0021] FIG. 3 is a graph illustrating the relationship between the negative pressure consumption rate and the inner diameter of the atmospheric air allowable hole 45. The negative pressure consumption rate [L / h] is the amount of air passing through the atmospheric air allowable hole 45 per unit time when the second passage 12 is at a predetermined negative pressure in the state shown in FIG. 1B. As shown in FIG. 3, the negative pressure consumption rate increases as the inner diameter [mm] of the atmospheric air allowable hole 45 increases. As described above, the lower limit of the negative pressure consumption rate is set to a value at which the behavior of the plunger 32 is stabilized when the plunger 32 moves from the second position to the first position and the valve element 36 opens the first passage 11. The inner diameter of the atmospheric air allowable hole 45 is set to a value equal to or greater than the lower limit corresponding to this lower limit. This prevents the negative pressure in the second passage 12 from becoming too large, stabilizing the behavior of the plunger 32 when it moves from the second position to the first position.

[0022] 1B, it becomes difficult to sufficiently supply negative pressure to the negative pressure actuator 102. For this reason, an upper limit is set for the negative pressure consumption, taking into consideration the supply of negative pressure to the negative pressure actuator 102. Therefore, the size of the inner diameter of the atmosphere allowing hole 45 is set to be equal to or less than the upper limit so as to correspond to the upper limit of the negative pressure consumption.

[0023] In addition, in the state of FIG. 1A, the atmosphere is introduced into the communication chamber 14 through the atmosphere allowance hole 45, but since the inner diameter of the atmosphere allowance hole 45 is sufficiently small compared to the suction force of the negative pressure pump 101, the effect on the supply of negative pressure to the negative pressure actuator 102 is small.

[0024] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as defined in the claims. [Explanation of symbols]

[0025] 1 Negative pressure adjustment valve 11 1st aisle 12 2nd aisle 13 3rd aisle 20 Negative pressure supply pipe 30 Electromagnetic Actuator 32 Plunger 36 Valve body 40 Isolation sleeve 45 Atmospheric Permitted Hole 101 Negative pressure pump 102 Negative pressure actuator

Claims

[Claim 1] a first passage communicating with a negative pressure pump; a second passage communicating with the negative pressure actuator; a third passage communicating with the atmosphere; a switching mechanism that switches between communication and blocking of the first, second, and third passages, The switching mechanism is a plunger that is moved to a first and second position by an electromagnetic actuator; a valve body held by the plunger; a blocking member held by the plunger and in contact with the valve body, When the plunger is in the first position, the valve body opens the first passage, connecting the first passage and the second passage, and the valve body and the blocking member block the third passage from the first and second passages, When the plunger is in the second position, the valve body closes the first passage to isolate the first passage from the second passage, and the valve body and the blocking member isolate the third passage from the first and second passages, When the plunger is at the first position and the first and second passages are under negative pressure due to the negative pressure pump, the plunger moves to the second position, and negative pressure acts on the valve body so as to keep the first passage closed, and the plunger moves to the first position against the negative pressure acting on the valve body, causing the valve body to open the first passage, the blocking member has an atmosphere allowing hole that allows the introduction of atmosphere from the third passage to the second passage so that the negative pressure in the second passage is reduced when the plunger is at the second position; an inner diameter of the atmosphere allowing hole set to a size that stabilizes the behavior of the plunger when it moves from the second position to the first position;

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