JP5607492B2 - Negative pressure pump - Google Patents

Description

  The present invention relates to a negative pressure pump, for example, a negative pressure pump that makes negative pressure in a negative pressure chamber of a negative pressure booster provided in a vehicle.

  An electric pump for automobiles has been proposed as this type of negative pressure pump (see, for example, Patent Document 1 (FIG. 2)).

  The negative pressure pump includes a rotor with a vane, a housing that houses the rotor with the vane, and a plate that closes the intake port side of the housing. A resonance space is provided between the housing and the plate. Intake noise at the intake port is reduced by the resonance effect of the resonance space.

  However, the sound generated when the vane strikes the housing easily leaks out of the housing. The sound of the vane leaking outside causes noise. Therefore, countermeasures against hammering are required.

JP 2007-16703 A

  An object of the present invention is to provide a technique capable of reducing noise by taking measures against the sound of vanes in a negative pressure pump.

The invention according to claim 1 is a negative pressure pump having a pump part in which a rotor and a vane are housed in a case, and a cover body covering the pump part.
The case has a hollow portion for suppressing the sound of the vane from being transmitted to the cover body side ,
The hollow portion also serves as an exhaust passage for passing exhaust generated in the rotor and the vane,
In the case, one opening is closed with a first lid and the other opening is closed with a second lid, and the rotor and the vane are provided between the first lid and the case. A first communication passage is provided for flowing the exhaust generated in step 1 to the exhaust passage .

  In the invention which concerns on Claim 2, it has a space part on the outer side of a hollow part, It is characterized by the above-mentioned.

In the invention according to claim 3 , the case has one opening closed by the first lid, the other opening closed by the second lid, and the case close to the second lid. A second communication passage is provided for discharging the exhaust gas flowing through the exhaust passage to the outside of the case and into the cover body.

In the invention according to claim 4 , the case is arranged such that one opening is closed by the first lid and the other opening is closed by the second lid, and is in contact with the second lid. The second connecting passage for discharging the exhaust gas to the body part is formed in the second lid.

In the invention according to claim 1, the case is provided with a hollow portion that suppresses transmission of the sound of the vane to the cover body.
The sound of the vane passing through the meat of the case is blocked by the hollow part. As a result, it is possible to suppress the sound of the base from leaking out of the pump unit. The leaking sound is further blocked by the cover body. With such a double sound insulation structure, it is possible to effectively reduce the sound of the vanes.
ADVANTAGE OF THE INVENTION According to this invention, the technique which can aim at reduction of a noise is provided in a negative pressure pump.
In addition, in the invention according to claim 1, the hollow portion is also used as an exhaust passage through which exhaust generated in the rotor and the vane is passed.
Since the hollow portion is also used as the exhaust passage, the negative pressure pump can be downsized as compared with the case where the exhaust passage is provided outside the pump portion.
Furthermore, in the first aspect of the invention, the exhaust generated in the rotor and the vane is caused to flow to the exhaust passage through the first communication passage provided between the case and the first lid.
Exhaust gas expands when it flows from the first communication passage into the exhaust passage (hollow portion). This expansion attenuates the acoustic energy held by the exhaust. As a result, exhaust noise can be greatly reduced.

  In the invention which concerns on Claim 2, it has a space part on the outer side of a hollow part. The sound of the vane passing through the case meat is blocked by the hollow portion, but the leaked sound is blocked by the space. With such a double sound insulation structure, it is possible to effectively reduce the sound of the vanes.

In the invention according to claim 3 , the exhaust gas flowing through the exhaust passage is discharged outside the case and into the cover body in the second communication passage provided in the case in the vicinity of the second lid. The exhaust gas expands when it is discharged from the second communication passage into the cover body. This expansion further attenuates the acoustic energy. As a result, exhaust noise can be greatly reduced.

In the invention which concerns on Claim 4 , the 2nd communicating path which discharges | emits exhaust_gas | exhaustion to the body part arrange | positioned in contact with the 2nd cover body is formed in the 2nd cover body. Accordingly, as in the fifth aspect, the processing of the case is reduced while reducing the exhaust noise, and the processing cost of the case can be reduced. In particular, the second lid is provided with a shaft hole through which the motor shaft passes. By processing at the same time as the shaft hole or the like, an increase in the processing cost of the second lid can be suppressed. Therefore, the total processing cost can be reduced.

1 is an exploded perspective view of a negative pressure pump according to Embodiment 1. FIG. It is a disassembled perspective view of a pump part. FIG. 3 is a view taken in the direction of arrow 3 in FIG. 2. It is principal part sectional drawing of a negative pressure pump. FIG. 5 is a sectional view taken along line 5-5 of FIG. It is a figure explaining the flow of the intake air from an intake port to a pump part. It is a figure explaining the flow of the exhaust from a connecting pipe to an exhaust port. It is a figure which shows the example of a change of a case. FIG. 4 is a cross-sectional view of a main part of a negative pressure pump according to a second embodiment.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. Although the negative pressure pump of the present invention is suitable for a negative pressure booster for vehicles, the application is arbitrary. The drawings are viewed in the direction of the reference numerals.

First, Embodiment 1 of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the negative pressure pump 10 is attached with a body portion 40 having an intake port 24 at the top, and a plurality of (two in this example) screws 26 on one side surface of the body portion 40. A motor 28 whose motor shaft 27 is an involute spline shaft, and a pump portion 70 which is attached by screwing long bolts 32 into a plurality (four in this example) of female screw holes 31 provided on the other side surface of the body portion 40. And a plurality of (four in this example) female screw holes provided on the other surface of the body portion 40 while covering the connection pipe 50 connected to the suction port 24 via the filter member 33 and the pump portion 70. 34 and a cover body 60 which is attached by screwing a screw 36.

  An intermediate connector 37 that supplies power to the motor 28 is provided on the side of the motor 28.

  Since the body portion 40 is a base for mounting the motor 28 and connecting to the vehicle, it is desired that the body portion 40 be made of a metal having a large thickness and high rigidity, such as a casting. A pair of fixing portions 41 attached to the vehicle-side bracket are provided on the bottom surface of the body portion 40 so as to protrude downward. A shaft hole 42 into which the motor shaft 27 is inserted is provided at the center of the body portion 40.

  A side surface of the body portion 40 to which the pump portion 70 is attached is referred to as a pump attachment side surface 43. A seal material 44 such as an O-ring is provided on the pump mounting side surface 43 along the outer periphery of the pump mounting side surface 43.

  A semicircular intake groove 46 centered on the shaft hole 42 is provided on the pump mounting side surface 43 from the upper side to the lower side of the shaft hole 42, and a sealing material such as an O-ring surrounds the intake groove 46. 47 is provided on the pump mounting side surface 43.

  The connecting pipe 50 includes a fastening portion 53 that is fastened by screwing screws 52 into a plurality (two in this example) of female screw holes 51 provided on the upper surface of the body portion 40, and projects upward from the fastening portion 53. The main part 55 and a hose insertion part 57 extending from the base part 55 in the axial direction 56 of the motor shaft 27 are connected to the suction port 24 through a sealing material 58 such as an O-ring.

  The cover body 60 is a bottomed cylinder, and includes a bottom portion 61 that faces the pump mounting side surface 43, a cylindrical portion 62 that extends from the bottom portion 61 toward the pump mounting side surface 43, and an end portion of the cylindrical portion 62 in a bowl shape. The flange portion 63 is formed.

  2 is an exploded perspective view of the pump unit 70. The pump unit 70 includes a non-circular rotor chamber 71 and a case 90 provided with a plurality (four in this example) of bolt holes 72, and a plurality of vane grooves 75. Are provided radially, and an involute spline hole 76 is provided at the center. The rotor 77 is rotatably accommodated in a rotor chamber 71 having a non-circular cross section, and the vane 78 is movably accommodated in a plurality of vane grooves 75. , A second lid 84 having a plurality (four in this example) of bolt holes 81 and two upper and lower intake holes 82, 82, and a first lid having a plurality of (four in this example) bolt holes 86. 87 and a plurality of (four in this example) bolts 32 that pass through the bolt holes 86, 72, 81.

  The rotor chamber 71 of the case 90 is substantially oval and is formed such that the long axis direction 91 is oriented vertically and the short axis direction 92 is oriented horizontally. A plurality (a pair in this example) of hollow portions 93 and 93 are provided on both sides of the rotor chamber 71 in the short axis direction 92. The hollow portions 93, 93 are holes that penetrate the case 90 along the axial direction of the motor shaft (a straight line indicated by reference numeral 57).

  The hollow portions 93, 93 are formed so as to be as wide as possible in the side wall portion 94. That is, the hollow portion 93 is formed with a width as large as possible from the vicinity of the upper bolt hole 72 to the vicinity of the lower bolt hole 72 within a range in which sufficient strength is ensured in the case 90. On both sides in the width direction of the hollow portion 93, a wall portion 96 on the rotor chamber 71 side and a wall portion 97 on the cover body (FIG. 1, reference numeral 60) side are formed.

  One opening of the case 90 is closed by the first lid 87, and the other opening is closed by the second lid 84.

The 2nd cover body 84 has the insertion hole 98 in which a motor shaft (FIG. 1, code | symbol 27) is inserted. The intake holes 82 are arranged so as to face each other with the insertion hole 98 interposed therebetween.
The first lid 87 has a pair of recesses 101, 101 on the surface on the case 90 side.

A semicircular cutout 102 is formed at the end of the wall 97 on the second lid 84 side.
As shown in FIG. 3, the notch 102 is disposed at a lower portion of one of the pair of wall portions 97 and 97. A semicircular cutout 102 is also provided on the upper portion of the other wall portion 97.

The configuration of each part of the negative pressure pump will be described in more detail based on FIG. 4 and FIG.
FIG. 4 is a cross-sectional view of the main part of the negative pressure pump 10 assembled based on FIGS. 2 and 1.
As shown in FIG. 4, a rolling bearing 103 is provided in the shaft hole 42, and the motor shaft 27 is supported by the bearing 103. The tip of the motor shaft 27 is fitted into the involute spline hole 76 of the rotor 77, and the tip reaches the vicinity of the first lid 87.

  The recesses 101, 101 are each formed with a width W greater than the thickness t of the wall 96. The first communication passages 104, 104 communicating the rotor chamber 71 and the hollow portion 93 are formed by the concave portions 101, 101 having the width W being joined to the end portions of the wall portions 96, 96.

  When the notches 102 and 102 are combined with the second lid body 84, second communication passages 106 and 106 that communicate the inside of the hollow portion 93 and the inside of the cover body 60 are formed. The hollow portions 93 and 93 serve as exhaust passages 107 and 107 that guide exhaust gas from the first communication passages 104 and 104 to the second communication passages 106 and 106.

  As shown in FIG. 5, pump chambers 111, 111 that are gaps between the rotor chamber 71 and the rotor 77 are formed at both ends of the rotor chamber 71 in the long axis direction 91. The intake holes 82 are arranged on a straight line 112 that is inclined at an angle θ1 with respect to the major axis direction 91. The intake holes 82 and 82 are arranged at positions corresponding to both ends of the intake groove (FIG. 1, reference numeral 46) and overlapping the pump chambers 111 and 111.

  The first communication passages 104 and 104 indicated by imaginary lines are on a straight line 113 inclined at an angle θ2 on the opposite side of the straight line 112 with respect to the long axis direction 91, and the pump chambers 111 and 111 and the hollow portions 93 and 93. It is arranged at the position that overlaps.

  In addition, each structure of an inlet hole, a 1st connection channel | path, a 2nd communication channel | path, and a hollow part, and inclination | tilt angle (theta) 1 and inclination | tilt angle (theta) 2 can be arbitrarily set according to the required pump performance.

  An exhaust outlet 114 is provided at the lowest position of the portion of the pump attachment side 43 covered with the cover body 60. An exhaust port 120 is provided directly below the exhaust outlet 114 and between the pair of fixing portions 41, 41.

The exhaust port 120 is formed by fitting a plug member 122 into the exhaust hole 121 from the outside and forming a plurality of exhaust passages 123 between the inner peripheral surface of the exhaust hole 121 and the outer peripheral surface of the plug member 122.
The exhaust outlet 114 and the exhaust 120 are communicated by a discharge passage 124.

The flow of intake / exhaust in the negative pressure pump described above will be described with reference to FIGS.
As shown in FIG. 7, when the motor (FIG. 1, reference numeral 28) operates, outside air is sucked into the connection pipe 50 by the suction action of the pump unit 70. The intake air passes through the filter member 33 and is sucked into the suction port 24 (arrow (1)).

  As shown in FIG. 6, the intake air that has entered the intake port 24 enters the pump unit 70 from one intake hole 82 (arrow (2)), or is pumped from the other intake hole 82 through the intake groove 46. Part 70 is entered (arrow (3)).

  The intake air that has entered the pump chambers 111, 111 from the intake holes 82, 82 is pressurized by the action of the plurality of vanes 78, and the exhaust passage 107, which is the hollow portions 93, 93, through the first communication passages 104, 104. It is discharged to 107 (arrows (4), (5)). At this time, the exhaust gas is throttled in the first communication passages 104 and 104 and then expanded in the exhaust passages 107 and 107. Then, the exhaust gas passes through the exhaust passages 107 and 107, is throttled again by the second communication passages 106 and 106, is discharged into the cover body 60, and expands again (arrows (6) and (7)).

  Returning to FIG. 7, the exhaust discharged into the cover body 60 passes over the pump part 70 (arrow (8)), or passes through the side of the pump part 70 (arrow (9)), or the cover. It passes between the bottom 61 of the body 60 and the pump part 70 (arrow (10)), and finally goes under the pump part 70 (arrow (11)).

  Exhaust gas that has flowed under the pump unit 70 enters the discharge passage 124 from the exhaust outlet 114 (arrow (12)) and, when reaching the plug member 122, avoids (bypasses) the plug member 122, thereby exhausting the exhaust passage. 123 is released into the atmosphere (arrow (13)).

According to the negative pressure pump acting as described above, the following effects can be obtained.
As shown in FIG. 6, the sound of the vane 78 transmitted to the walls 96 and 96 is blocked by the air layer interposed in the hollow portion 93. As a result, the sound of the vanes 78 can be prevented from leaking out of the pump unit 70. The leaking sound is blocked by the space 126 in the cover body 60. As a result, further noise reduction of the negative pressure pump 10 can be achieved.

  Further, since the hollow portions 93 and 93 are also used as the exhaust passages 107 and 107, the negative pressure pump can be downsized as compared with the case where the exhaust passage is provided outside the pump portion.

  Further, the exhaust gas expands when it flows from the first communication passages 104 and 104 into the hollow portions 93 and 93 (exhaust passages 107 and 107). This expansion attenuates the acoustic energy held by the exhaust. Next, the exhaust gas expands when it is discharged from the second communication passages 106 and 106 into the cover body 60. This expansion further attenuates the acoustic energy. As a result, exhaust noise can be greatly reduced.

Next, a case modification example will be described with reference to the drawings.
FIG. 8 is a diagram for explaining a modification of the case indicated by reference numeral 90 in FIG. The difference from the case 90 is that a hollow portion is further added to the case. The rest of the configuration is the same as that in FIG. 2, and the detailed description is omitted by using the reference numerals in FIG. 2.

  As shown in FIG. 8, in the case 90 </ b> B, in addition to the hollow portions 93 and 93, the hollow portions 93 </ b> B and 93 </ b> B are provided on both sides in the long axis direction 91 of the rotor chamber 71. By adding the hollow portions 93B and 93B, the rotor chamber 71 is surrounded by the plurality of hollow portions 93 and 93B over the entire circumference. The sound of vanes transmitted to the walls 96, 96 is blocked by the air layer interposed in the hollow portions 93, 93B. As a result, the sound insulation effect is improved, and it is possible to further suppress the sound of the vane from leaking out of the pump portion (FIG. 6, reference numeral 70).

Next, a second embodiment of the present invention will be described. The changes from FIG. 4 are as follows.
The second communication passage 106 that is notched in the wall 97 in FIG. 4 is transferred to the second lid 128.

  That is, as shown in FIG. 9, one opening of the case body 90 is closed by the first lid body 127, and the other opening is closed by the second lid body 128. The second communication passages 106 and 106 are formed to penetrate the shaft 27 so as to be parallel to the shaft 27. A discharge passage 124 connected to the second communication passages 106 and 106 is formed in the body portion 40. The body portion 40 is provided with an exhaust port 120 whose main part is the plug member 122, and an outlet of the discharge passage 124 is connected to the exhaust port 120.

  The intake air is pressurized by the action of the vane 78 and is discharged to the exhaust passages 107 and 107 which are the hollow portions 93 and 93 through the first communication passages 104 and 104. At this time, the exhaust gas is throttled in the first communication passages 104 and 104 and then expanded in the exhaust passages 107 and 107. The exhaust gas passes through the exhaust passages 107 and 107, passes through the second communication passages 106 and 106, passes through the discharge passage 124, and reaches the exhaust port 120. Exhaust gas is discharged from the exhaust passage 123 into the atmosphere at the exhaust port 120 so as to avoid (bypass) the plug member 122.

In FIG. 9, the exhaust noise is blocked by the air layer interposed in the space 126 in the cover body 90, so that the exhaust noise can be reduced as in FIG. 4.
Furthermore, in FIG. 9, the second communication passage 106 is formed in the second lid 128. Processing to the case 90 is reduced, and the processing cost of the case 90 can be reduced. In particular, the second lid 128 is provided with a shaft hole 42 through which the motor shaft 27 is passed. By processing at the same time as the shaft hole 42 and the like, an increase in the processing cost of the second lid 128 can be suppressed. Therefore, the total processing cost can be reduced.

  In the present embodiment, two or four hollow portions are provided in the case, but the number of hollow portions may be one, three, five or more.

  Further, the negative pressure pump of the present invention is not particularly limited to the type of pump, and the type is arbitrary as long as it is a pump in which a rotor and a vane are housed in a case.

  Further, the negative pressure pump of the present invention is suitable for a negative pressure pump for a vehicle for making negative pressure in a negative pressure chamber of a negative pressure booster provided in the vehicle, but the application is not particularly limited. It can be applied to general machines, general-purpose machines, and general equipment.

  The negative pressure pump of the present invention is suitable for a negative pressure pump for a vehicle for making negative pressure inside a negative pressure chamber of a negative pressure booster provided in the vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Negative pressure pump, 40 ... Body part, 60 ... Cover body, 70 ... Pump part, 77 ... Rotor, 78 ... Vane, 84, 128 ... 2nd cover body, 87, 127 ... 1st cover body, 90, 90B ... Case, 93, 93B ... Hollow part, 104,104 ... First communication passage, 106,106 ... Second communication passage, 107 ... Exhaust passage.

Claims (4)

In a negative pressure pump having a pump part that houses a rotor and a vane in a case, and a cover body that covers the pump part,
The case has a hollow portion for suppressing the sound of the vane from being transmitted to the cover body side ,
The hollow portion also serves as an exhaust passage for passing exhaust generated in the rotor and the vane,
In the case, one opening is closed with a first lid and the other opening is closed with a second lid, and the rotor and the vane are provided between the first lid and the case. A negative pressure pump, characterized in that a first communication passage is provided for flowing the exhaust gas generated in step 1 to the exhaust passage . The negative pressure pump according to claim 1,
A negative pressure pump having a space outside the hollow portion. The negative pressure pump according to claim 1 or 2 ,
The case has one opening closed by a first lid and the other opening closed by a second lid, and flows through the exhaust passage to the case in the vicinity of the second lid. A negative pressure pump, characterized in that a second communication passage is provided for discharging exhaust gas outside the case and into the cover body. The negative pressure pump according to claim 1 or 2 ,
In the case, one opening is closed with a first lid, and the other opening is closed with a second lid, and exhaust is discharged to a body portion arranged in contact with the second lid. A negative pressure pump, wherein a second communication passage is formed in the second lid.

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