JP2013148063A - Negative pressure pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a negative pressure pump capable of canceling any resonance sound with a cover body.SOLUTION: Holes 75 are formed in a flange part 73 of a cover body 70, and collars 76 are inserted in these holes 75. A metal ring 30 is abutted on the flange part 73, a screw 36 is passed through the metal ring 30 and the collar 76, and tightened to a body part 40, and the cover body 70 is mounted on the body part 40. The cover body is formed of an elastic rubber material. Since it is assumed that an electric negative pressure pump is installed in an engine room, its material is preferably high in heat resistance, cold resistance, weather resistance, and chemical resistance, in particular, ethylene propylene rubber (EPDM) is preferable. The rubber material has elasticity, and the vibration from the body part is absorbed by the cover body itself. As a result, the resonance sound with the cover body can be canceled thereby.

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.

  As a kind of negative pressure pump, a negative pressure pump that generates a negative pressure by a rotor with a vane has been proposed (see, for example, Patent Document 1 (FIG. 1)).

The technique of this patent document 1 is demonstrated below based on drawing.
FIG. 10 is a cross-sectional view of a conventional negative pressure pump 200. When the motor 201 is operated and the rotor 202 and the vane are rotated, air is sucked into the pump unit 204 from the intake port 203 and is pressurized by the vane. Is discharged into the exhaust chamber 206 inside the cover body 205 through the discharge port. The air discharged into the exhaust chamber 206 is exhausted from the exhaust port 207.

The cover body 205 is a member that forms the exhaust chamber 206, and also serves as a cover that prevents contamination (dirt) and moisture from entering the exhaust chamber 206 from the outside, and a role that blocks pump sound generated by the pump unit 204. It is the member which fulfills.
The cover body 205 that covers the pump unit 204 is generally formed of aluminum, resin, or the like in order to prevent contamination or moisture from being mixed into the pump unit 204 and for sound insulation.

  However, if the cover body 205 is formed of aluminum or resin, the cover body may resonate due to vibration from the body portion 208, and resonance sound may be generated. That is, there is a demand for a negative pressure pump that can mute the resonance with the cover body.

JP 2010-236503 A

  This invention makes it a subject to provide the negative pressure pump which can mute the resonance sound with a cover body.

  The invention according to claim 1 includes a body portion as a base, a pump portion attached to one side surface of the body portion, and a cover attached to one side surface of the body portion having a storage chamber surrounding the pump portion. In a negative pressure pump comprising a body, the cover body is formed of a rubber material having elasticity.

  In the invention according to claim 2, the cover body is provided with a flange portion in contact with the body portion, a metal ring is applied to the flange portion, and the flange portion is attached to the body portion via the metal ring. .

According to the first aspect of the present invention, in the negative pressure pump including the cover body having the accommodating chamber surrounding the pump portion and attached to one side surface of the body portion, the cover body is formed of a rubber material having elasticity.
Since the rubber material has elasticity, the cover body itself absorbs vibration from the body portion. As a result, the resonance sound with the cover body can be silenced.

In the invention according to claim 2, the cover body is provided with a flange portion in contact with the body portion, a metal ring is applied to the flange portion, and the flange portion is attached to the body portion via the metal ring.
Since the flange portion is sandwiched between the metal rings, the displacement of vibration entering the flange portion can be suppressed, and vibration can be more effectively prevented.
In addition, when the metal ring is held down with a bolt, the flange portion can be brought into close contact with the body portion other than the bolt portion, air leakage can be prevented, and sound insulation is improved.

It is a figure which shows the example of arrangement | positioning of the negative pressure pump which concerns on this invention. It is a disassembled perspective view of a negative pressure pump. It is a disassembled perspective view of a pump part. It is sectional drawing of a negative pressure pump. It is sectional drawing of a flange part. It is a figure explaining the attachment state of a metal ring. It is a figure explaining the effect | action of a negative pressure pump. It is a figure explaining the other aspect of FIG. FIG. 9 is a sectional view taken along line 9-9 in FIG. 8. It is a principle diagram of a conventional negative pressure pump.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

First, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the negative pressure pump 10 of the present invention is a kind of vacuum pump that makes negative pressure in a negative pressure chamber 12 of a negative pressure booster 11 provided in a vehicle.
When the negative pressure pump 10 is operated, the negative pressure pipe 13, the negative pressure chamber 12, and the variable pressure chamber 14 are at negative pressure. When the brake pedal 16 is depressed in this state, the negative pressure chamber 12 and the variable pressure chamber 14 are cut off, air is introduced into the variable pressure chamber 14, and the diaphragm 17 is returned to the return spring by the differential pressure between the negative pressure chamber 12 and the variable pressure chamber 14. 18 is deformed to the compression side and push rod 19 is pushed out. As a result, a large braking force can be obtained with a small pedal effort. The negative pressure pump 10 is fixed to the bracket 21 on the vehicle side with bolts 22.

The structure of the negative pressure pump 10 will be described in detail below.
As shown in FIG. 2, the negative pressure pump 10 includes a body portion 40 having the suction port 24 at the top, and a plurality (four in this example) of female screw holes provided on one side surface 38 of the body portion 40. The pump part 80 attached by screwing a long bolt 32 into the screw 31, the connection pipe 60 connected to the suction port 24 via the filter member 33, the pump part 80 and the one side surface 38 of the body part 40. A cover body 70 attached via a metal ring 30 by screwing screws 36 into a plurality (four in this example) of female screw holes 34 provided, and a plurality (in this example, the other side 39 of the body portion 40). The motor shaft 27 is attached with two screws 26 and the motor shaft 27 is an involute spline shaft. The cover body 70 is formed of a rubber material having elasticity (details will be described later).

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. On the bottom surface of the body portion 40, a pair of fixing portions 41 attached to a vehicle-side bracket (FIG. 1, reference numeral 21) via bushes are provided 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 unit 80 is attached is referred to as one side surface 38. A sealing material 44 such as an O-ring is provided on the one side surface 38 along the outer periphery of the one side surface 38.

  In addition, a semicircular intake groove 46 centered on the shaft hole 42 is provided on one side surface 38 from the upper side to the lower side of the shaft hole 42, and a sealing material such as an O-ring is provided so as to surround the intake groove 46. 47 is provided on one side 38.

  Further, a plurality of (four chambers in the embodiment) chambers 51 to 54 are provided on one side surface 38. The plurality of chambers 51 to 54 are disposed at the center in the vertical direction of the body portion 40, and are disposed between the first chamber 51 formed along the outer periphery of the body portion 40 and the first chamber 51 and the shaft hole 42. A second chamber 52 communicating with the first chamber 51 via the first communication groove 55, and a third chamber disposed below the shaft hole 42 and communicating with the second chamber 52 via the second communication groove 56. 53 and a fourth chamber 54 that is communicated via the third communication groove 57 immediately below the third chamber 53 and is formed along the outer periphery of the body portion 40.

  The connecting pipe 60 includes a fastening portion 63 that is fastened by screwing screws 62 into a plurality of (two in this example) female screw holes 61 provided on the upper surface of the body portion 40, and projects upward from the fastening portion 63. The main portion 65 and the hose insertion portion 66 extending from the base portion 65 in the axial direction 67 of the motor shaft 27 are connected to the suction port 24 via a sealing material 68 such as an O-ring.

  The cover body 70 is a bottomed cylinder, and includes a bottom portion 71 that faces one side surface 38, a cylindrical portion 72 that extends from the bottom portion 71 toward the one side surface 38, and an end portion of the cylindrical portion 72 in a bowl shape. The flange portion 73 is formed.

  FIG. 3 is an exploded perspective view of the pump unit 80. The pump unit 80 includes a non-circular rotor chamber 81, a case 83 provided with a plurality (four in this example) of bolt holes 82, and a plurality of vane grooves 84. Are provided in a radial manner, and an involute spline hole 85 is provided at the center thereof. , An intake plate 94 having a plurality (four in this example) of bolt holes 91 and two upper and lower intake holes 92, 93, and a plurality (four in this example) of bolt holes 95 and two upper and lower exhaust holes 96. , 97 and a plurality (four in this example) of bolts 32 passed through the bolt holes 95, 82, 91.

The configuration of each part of the negative pressure pump will be described in more detail based on FIG.
FIG. 4 is a cross-sectional view of the negative pressure pump 10 assembled based on FIGS. 2 and 3.
As shown in FIG. 4, a rolling bearing 102 is provided in the shaft hole 42, and the motor shaft 27 is supported by the bearing 102. The tip of the motor shaft 27 is fitted into the involute spline hole 85 of the rotor 86, and the tip reaches the vicinity of the exhaust plate 98.

The flange portion 73 of the cover body 70 is in contact with the entire circumference of the sealing material 44, and the sealing material 44 ensures airtightness in the cover body 70.
On the other hand, the surface of the intake plate 94 is in contact with the entire circumference of the sealing material 47, and the opening of the intake groove 46 is blocked by the sealing material 47 and the intake plate 94, thereby forming the intake passage 103. As a result, an intake path including the connection pipe 60, the intake port 24, the intake passage 103, and two intake holes (FIG. 3, reference numerals 92 and 93) is formed.

  A communication hole 59 through which exhaust gas passes from the fourth chamber chamber 54 to the discharge port 58 is provided. A housing chamber 74 that houses the pump unit 80 is formed inside the cover body 70.

Next, attachment of the cover body 70 will be described in detail.
As shown in FIG. 5, holes 75 are provided in the flange portion 73 of the cover body 70, and the collar 76 is inserted into these holes 75. The cover body 70 is attached to the body portion 40 by applying the metal ring 30 to the flange portion 73 and tightening the metal ring 30 and the collar 76 through the screw 36 to the body portion 40.

  The cover body is made of a rubber material having elasticity. The rubber material is composed of natural rubber, silicone rubber, urethane rubber, fluorine rubber, chlorobrene rubber, nitrile butadiene rubber, ethylene propylene rubber, styrene butadiene rubber, and the like. Since the electric negative pressure pump is assumed to be installed in an engine room, a material having high heat resistance, cold resistance, weather resistance, and chemical resistance is desirable, and ethylene propylene rubber (EPDM) is particularly desirable. In addition, the smaller the dynamic spring constant, the smaller the transmission vibration and the inherent transmission sound, and the vibration damping effect and the noise reduction effect can be obtained.

Next, the operation of the metal ring 30 will be described.
As shown in FIG. 6, the metal ring 30 is applied from above the entire flange portion 73 of the cover body 70. Since the whole flange part 73 is inserted | pinched with the metal ring 30, the displacement of the vibration which enters into the flange part 73 can be suppressed, and it can isolate more effectively.
In addition, when the metal ring 30 is held down with the screws 36 (bolts 36), the flange portion 73 can be brought into close contact with the body portion 40 in portions other than the screws 36, air leakage can be prevented, and sound insulation is improved. .

The operation of the negative pressure pump described above will be described next.
As shown in FIG. 7, when the motor (FIG. 2, reference numeral 28) operates, the outside air is sucked into the connection pipe 60 by the suction action of the pump unit 80 and flows into the suction port 24 (arrow (1)).

  The intake air that has entered the intake port 24 enters the pump unit 80 through the intake hole 92 and is pressurized and discharged from the exhaust hole 96 (arrow (2)), or is pumped from the intake hole 93 through the intake passage 103. Part 80 is pressurized and discharged from the exhaust hole 97 (arrow (3)). Exhaust gas discharged from the upper and lower exhaust holes 96 and 97 flows into the cover body 70.

  The cover body 70 is formed of a rubber material having elasticity. Since the rubber material has elasticity, the cover body 70 itself absorbs vibration from the body portion 40. As a result, the resonance sound with the cover body 70 can be silenced.

Next, another aspect of FIG. 5 will be described. In addition, the same code | symbol is attached | subjected about the same structure as the structure shown in FIG. 5, and detailed description is abbreviate | omitted.
As shown in FIG. 8, a plurality of convex portions 112 are provided inside the cover body 70. By providing the convex portion 112, the sound absorption area can be expanded and the sound absorption can be improved.

  As shown in FIG. 9, a plurality of convex portions 112 are provided on the bottom 71 of the cover body 70. The size and arrangement of the projections 112 are not limited to the embodiment, and the size and arrangement of the projections 112 may be different from those of the embodiment as long as they have sound absorption.

In the embodiment, the vane pump is described as the negative pressure pump. However, the negative pressure pump is not limited to the vane pump.
Furthermore, the negative pressure pump of the present invention is suitable for a negative pressure pump for a vehicle for making the negative pressure chamber of a negative pressure booster provided in the vehicle negative pressure, but it is not intended to limit the application. However, 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, 30 ... Body part, 34 ... One side surface (upper surface), 50 ... Cover body, 51 ... Storage chamber, 53 ... Compartment room (silence chamber), 70 ... Motor, 72 ... Motor shaft, 75 DESCRIPTION OF SYMBOLS ... Motor case, 80 ... Pump part, 104 ... Exhaust path, 105 ... Communication path, 106 ... Air path, 107 ... Inlet, 108 ... Crevice, 109 ... Bank part.

Claims (2)

In a negative pressure pump comprising a body portion as a base, a pump portion attached to one side surface of the body portion, and a cover body having a storage chamber surrounding the pump portion and attached to one side surface of the body portion ,
The said cover body is formed with the rubber material which has elasticity, The negative pressure pump characterized by the above-mentioned. The negative pressure pump according to claim 1,
The said cover body is provided with the flange part which contact | connects the said body part, a metal ring is applied to this flange part, and the said flange part is attached to the said body part via this metal ring, The negative pressure pump characterized by the above-mentioned.

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