JP2010236501A - Negative pressure pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative pressure pump enabling the water or the like intruded therein to be easily discharged. <P>SOLUTION: A plurality of through holes 85-87 allowing a first discharge chamber 97 and a second discharge chamber 98 to communicate with each other are provided to the negative pump. The plurality of through holes 85-87 have a height difference Δh2 therebetween so that one through hole 85 is higher than the upper end of the other through hole 87, and a height difference Δh1 therebetween so that one through hole 86 is higher than the upper end of the other through hole 87. Therefore, even if water intrudes into the second discharge chamber from the outside, and the water further intrudes into the first discharge chamber nearer the pump part through the through holes, the other through hole allows the air to flow therethrough since the higher through hole (the other through hole) is not closed, and the action of discharge of an exhaust pump can be maintained, i.e., the intrusion of water or the like into the pump part can be delayed and suppressed. <P>COPYRIGHT: (C)2011,JPO&INPIT

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.

FIG. 17 is a principle diagram of a conventional booster brake device.
The basic brake operation is that when the brake pedal 200 is depressed, the push rod 201 is pushed, the master cylinder 202 is operated by the push rod 201, and high-pressure brake fluid is supplied from the brake oil passages 203 and 203 to the wheel brake. Is done. In general, a booster brake device 210 is used to reduce the operating force of the operator.

  The booster brake device 210 is connected to a negative pressure booster 213 housing a diaphragm 211 and a return spring 212, a negative pressure pipe 215 extending from the negative pressure chamber 214 of the negative pressure booster 213, and a tip of the negative pressure pipe 215. A negative pressure pump 216. An electric air pump for automobiles has been proposed as this type of negative pressure pump 216 (see, for example, Patent Document 1).

  When the negative pressure pump 216 is operated, the negative pressure pipe 215, the negative pressure chamber 214, and the variable pressure chamber 217 are at negative pressure. When the brake pedal 200 is depressed in this state, the negative pressure chamber 214 and the variable pressure chamber 217 are cut off, air is introduced into the variable pressure chamber 217, and the diaphragm 211 is returned to the return spring by the differential pressure between the negative pressure chamber 214 and the variable pressure chamber 217. 212 is deformed to the compression side, and push rod 201 is pushed out. As a result, a large braking force can be obtained with a small pedal effort.

The technique of Patent Document 1 will be described with reference to the following diagram.
FIG. 18 is a cross-sectional view of a conventional negative pressure pump. In the negative pressure pump 216, when the rotor 218 with vanes is rotated by the motor 217, the pump inlet 219 becomes negative pressure. The air sucked through the pump inlet 219 is pressurized by the vane rotor 218, and the pressurized air is stored in the cover unit 220. The air stored here is discharged from the pump discharge port 221 to the atmosphere.

By the way, when traveling in the rain, a large amount of moisture is contained in the air around the negative pressure pump 216 mounted on the vehicle.
If the motor 217 stops during traveling in the rain, moisture may enter the cover 220 or the rotor 218 with vanes, and the operability may be impaired.

However, since the number of pump discharge ports 221 provided in the negative pressure pump 216 is one, when water or the like enters from the pump discharge port 221 particularly when the pump is stopped, the water or the like is difficult to escape. There is a high possibility that water or the like staying without escaping enters the rotor 218 with vanes.
Further, in the negative pressure pump 216, the crank passage 222 is provided in order to prevent intrusion of water or the like. However, since the pump discharge port 221 is one, it is difficult for water or the like that has entered once to escape, which causes a problem. It becomes.

US Pat. No. 6,491,505

  An object of the present invention is to provide a negative pressure pump in which water is difficult to enter and water is easily removed even if water enters.

The invention according to claim 1 is a negative pressure pump provided with a plurality of exhaust chambers on the outlet side of the pump unit, wherein the plurality of exhaust chambers are connected in series with through holes,
The plurality of exhaust chambers include a second exhaust chamber having at least a final exhaust port that exhausts air to the outside, and a first exhaust gas that is provided adjacent to the second exhaust chamber on the outlet side of the pump unit by a partitioning portion. An exhaust chamber,
The plurality of through holes are provided with a difference in height so that the other through hole is higher than the upper end of one through hole.

  In the invention which concerns on Claim 2, the upper surface of a partition part is made into step shape, and the said through-hole is each provided in the lower step part and the upper step part, It is characterized by the above-mentioned.

In the invention according to claim 1, a plurality of through holes that communicate the upper first exhaust chamber and the lower second exhaust chamber are provided in the partition portion. The height difference is provided so that the other through hole is higher than the upper end of the through hole.
Even if water enters the second exhaust chamber from the outside and this water further enters the first exhaust chamber closer to the pump portion through the through hole, the higher through hole (the other through hole) is blocked. Therefore, air can flow through the other through hole, and the exhaust action of the exhaust pump can be maintained. That is, according to the present invention, entry of water or the like into the pump unit can be delayed, and entry of water or the like into the pump unit can be suppressed.

Further, the water accumulated on the upper surface of the partitioning portion can be smoothly dropped into the second exhaust chamber through the lower through hole (one through hole), and the final exhaust port can be drained and discharged outside.
Therefore, according to the present invention, it is possible to provide a negative pressure pump in which water is unlikely to enter and water can easily escape even if water enters.

  In the invention which concerns on Claim 2, the upper surface of a partition part is made into step shape, and the through-hole is each provided in the lower step part and the upper step part. It is only necessary to make holes in the lower and upper steps, and through holes having different upper surface heights can be easily formed.

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 an external view of a negative pressure pump. It is a figure explaining an exhaust chamber lid. It explains the structure of the second exhaust chamber. It is principal part sectional drawing of a negative pressure pump. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. It is an expanded sectional view of a motor shaft. It is a figure explaining the arrangement | sequence of a volt | bolt. It is the 11-11 line sectional view of FIG. It is a principal part enlarged view of FIG. It is a figure explaining the structure and effect | action of a non-return valve. It is a figure explaining the effect | action at the time of a motor stop. It is operation | movement explanatory drawing that there are multiple final exhaust ports. It is a figure which shows the example of a change of FIG. It is a principle diagram of a conventional booster brake device. It is sectional drawing of the conventional negative pressure pump.

  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.

Embodiments 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 19 are negative. When the brake pedal 20 is depressed in this state, the negative pressure chamber 12 and the variable pressure chamber 19 are shut off, and air is introduced into the variable pressure chamber 19, and the diaphragm 14 is returned to the return spring by the differential pressure between the negative pressure chamber 12 and the variable pressure chamber 19. 15 is deformed to the compression side, and the push rod 16 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 17 on the vehicle side with bolts 18.

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 motor 22 in which the motor shaft 21 is an involute spline shaft, and a base plate 25 having screw holes 24 and 24 to which the motor 22 can be attached with screws 23 and 23. The pump part 50 is attached by screwing a total of four long bolts 28 into the first female screw holes 26, 26 and the second female screw holes 27, 27 provided on the surface of the base plate 25, and the pump part 50. And a cover part 70 that is attached by screwing screws 71 into third female screw holes 29 (four in total) provided on the surface of the base plate 25, and an inlet part 72 of the cover part 70 that is detachably inserted. The check valve 100, the filter 35, and the connection part (connection part) 40 are configured.

The base plate 25 is a base for mounting the motor 22 and the like and for connecting to the vehicle body, and it is desirable that the base plate 25 be made of a metal that is thick and has high rigidity.
On the other hand, the cover part 70 can be a resin molded product. If it is a resin molded product, an exhaust chamber (detailed later) having a complicated structure can be easily manufactured.

  The base plate 25 is integrally provided with screw seats 31 and 31 so as to be fixed to the vehicle, and a round hole 33 is provided at the center so that the columnar boss 32 of the motor 22 can be fitted.

Further, the first female screw hole 26 has a larger diameter than the second female screw hole 27, and the positioning hollow pins 34, 34 can be inserted therein. The operation of the positioning hollow pin 34 will be described later.
The filter 35 has a flat plate shape in which the edge of the net portion 36 is surrounded by a ring portion 37.

  The connection part 40 is a connection member to which a negative pressure pipe (FIG. 1, reference numeral 13) is connected, and can be fixed to the cover part 70 with a screw 41 so as to be detachable, and has a hose insertion part 42 in this example.

  FIG. 3 is an exploded perspective view of the pump unit 50. The pump unit 50 is provided with a rotor chamber 51 having a non-circular cross section, and a plurality (four in this example) of bolt holes 52 and 53 (however, the bolt holes 52 are Since the hole diameter corresponds to the positioning hollow pin, the diameter is larger than that of the bolt hole 53.) and a plurality of vane grooves 55 are provided radially, and an involute spline hole 56 is provided at the center. A rotor 57 rotatably accommodated in the rotor chamber 51 having a non-circular cross section, a vane 58 movably accommodated in the plurality of vane grooves 55, and a plurality of bolt holes 59, 59. The front lid 61 provided with the pump-in holes 60 and 60 and a plurality of bolt holes 62 and 63 (the bolt hole 62 has a diameter larger than that of the bolt hole 63 because the bolt hole 62 has a diameter corresponding to the positioning hollow pin. is there.) Two pump-out holes 64, 64 are provided, a bottom lid 66 is provided with an out groove 65 radially outward from the pump-out hole 64, and a rotor 57 and a vane 58 are accommodated in the case 54. In the state where the front and rear sides are closed by the front lid 61 and the bottom lid 66, a plurality of (four in this example) long bolts 28 passed through the bolt holes 59, 52 (or 53), 62 (or 63). Become.

The external appearance of the assembled negative pressure pump 10 based on FIGS. 3 and 2 is as shown in FIG. 4, and the motor 22 is attached to the base plate 25 with screws 23, and an intermediate connector 130 for supplying power to the motor 22. Are attached with screws 131 and a cover part 70 is attached with screws 71.
A part of the cover part 70 is extended to the lower left of the figure with a cylindrical (in this example, rectangular tube-shaped) exhaust chamber wall 73, and the end of the exhaust chamber wall 73 is closed with an exhaust chamber lid 74.

  As shown in FIG. 5, the exhaust chamber lid 74 is rectangular and has a lid main body 76 having a spherical portion 75 recessed toward the cover portion 70 at the center, and an edge of the lid main body 76 toward the cover portion 70 side. It consists of extended insertion pieces 77 (the number of insertion pieces 77 is four) and claws 78 provided on each of the insertion pieces 77. The adjacent insertion piece 77 and the insertion piece 77 are not connected to each other, and the gap 79 becomes a part of the exhaust passage. Since the exhaust chamber lid 74 has a complicated shape, a resin is preferable to a metal. If it is a resin molded product, it can be made into a lightweight and complicated shape.

  On the other hand, a final exhaust port 81 (four in this example) having a U-shaped cross section is formed at the tip of the exhaust chamber wall 73, and a plurality (for example, six) of engaging portions 82 are provided on the inner surface of the exhaust chamber wall 73. ing. By engaging the claws 78 with these engaging portions 82, the exhaust chamber lid 74 is fixed to the exhaust chamber wall 73. In principle, the exhaust chamber lid 74 cannot be removed. After the exhaust chamber lid 74 is attached, the final exhaust port 81 having a U-shaped cross section becomes a four-sided (rectangular) exhaust port.

In the exhaust chamber wall 73, an annular convex portion 84 that protrudes toward the exhaust chamber lid 74 is provided, and a single first through hole 85 is provided through the annular convex portion 84. The second through holes 86 and 86 and the third through hole 87 are provided on the inner side.
The exhaust chamber 90 (FIG. 7) is divided into a plurality of exhaust chambers, in the embodiment, a first exhaust chamber 97 and a second exhaust chamber 98 by a partition portion 88, and the first exhaust chamber 97 and the second exhaust from the rotor chamber 51 side. Chambers 98 are arranged in series.

These through holes 85 to 87 are formed so as to penetrate through the partition portion 88 and will be described later. A first exhaust chamber 97 is provided in the back of the partition portion 88, and a final exhaust port described later is disposed in front of the partition portion 88. There is a second exhaust chamber 98 that exhausts to the outside at 81, and serves to communicate these two exhaust chambers.
The partition portion 88 is provided with barriers 89 (four) on the outer side of the annular convex portion 84.

The operation of the barrier 89 will be described with reference to FIG.
Four through holes 85, 86, 86, 87 are provided in the exhaust chamber wall 73, and exhaust fluid (air) flows from the back of the drawing to the front during exhaust. The discharged fluid is discharged from the final exhaust port 81 through the route indicated by the arrows (1) and (2).

  On the other hand, since the final exhaust port 81 is open to the atmosphere, water may enter the exhaust chamber wall 73 from the outside. In that case, the intruding water first collides with the insertion piece 77 as shown by the arrow (3). After that, the direction is changed by 90 ° and passes through the gap 91 between the end of the barrier 89 and the insertion piece 77 as shown by the arrow (4). Alternatively, part of the intruding water passes through the gap 92 between the outer surface of the barrier 89 and the insertion piece 77 as indicated by an arrow (5). As described above, the inside of the second exhaust chamber 98 is formed into a labyrinth shape, thereby preventing moisture from entering the first exhaust chamber 97.

Next, the cross-sectional structure of the main part of the negative pressure pump shown in FIG. 4 will be described.
As shown in FIG. 7, the flange 93 of the motor 22 and the base plate 25 are sealed with a sealing material 94 such as an O-ring. Similarly, the space between the cover portion 70 and the base plate 25 is also sealed with a sealing material 95. Further, the space between the cover portion 70 and the front lid 61 is sealed with a sealing material 96.

The motor 22 is accurately positioned with respect to the base plate 25 by fitting the cylindrical boss 32 into the round hole 33. That is, the center of the motor shaft 21 matches the center of the round hole 33. The motor shaft 21 is engaged with the rotor 57 after passing through the bottom cover 66.
A first exhaust chamber 97 is provided below the case 54 that houses the rotor 57, and a second exhaust chamber 98 is provided below the first exhaust chamber 97.

Next, the attachment structure of the connection part 40, the filter 35, and the check valve 100 will be described.
First, the connecting part 40 is provided so as to be removable by being inserted into the inlet part 72 of the cover part 70 from above. It is fixed. In addition, up and down, front and back are indicated by arrows clearly shown in the figure.
The filter 35 is sandwiched between the connecting portion 40 and the check valve 100.

Next, the cross-sectional structure of the pump unit 50 will be described with reference to FIG. 8 which is a cross-sectional view taken along line 8-8 in FIG.
A rotor 57 is attached to the motor shaft 21, and a vane 58 is movably attached to the rotor 57. The rotor 57 is housed in a case 54, and the case 54 is surrounded by a cover 70. Then, it is understood that the exhaust chamber lid 74 is attached to the opening of the exhaust chamber wall 73 so that it cannot be removed by engaging the claw 78 with the engaging portion 82.

  The fitting relationship between the motor shaft 21 and the rotor 57 is an involute spline shaft in which the motor shaft 21 has six involute teeth 99 (extending in the front and back direction in the drawing) as shown in FIG. A corresponding involute spline hole 56 is provided in the center of the rotor 57.

  The involute tooth 99 has a curved tooth surface and has an action (alignment action) for aligning the center of the rotor 57 with the center of the motor shaft 21. That is, even if the center of the rotor 57 is deviated from the center of the motor shaft 21 during rotation, the center of the rotor 57 is automatically aligned with the center of the motor shaft 21 by the aligning action. When the centers match in this way, there will be no shake.

  The uneven wear in the rotor chamber 51 of the rotor 57 is eliminated, and the durability of the negative pressure pump itself is improved. At this time, in FIG. 2, after the motor 22 including the motor shaft 21 is assembled in advance, the motor shaft 21 is fitted to the rotor 57 together with the base plate 25. Therefore, since the centers of the motor shaft 21 and the rotor 57 are aligned by the aligning action only by assembling the motor 22, the assembling becomes easy.

Incidentally, in FIG. 8, the centers of the four bolts 28 are not arranged at the vertices of a square or a rectangle. The reason for this will be described next.
As shown in FIG. 10 (a), the bolt holes 59a to 59d (a to d are added to the reference numeral 59 for the sake of clarity) include at least one bolt hole 59b in the embodiment. 59d are arranged out of phase.

  If the front lid 61 is applied to the case 54 with the front and back reversed, all the bolt holes 59a to 59d are displaced from the bolt holes 52 and 53 on the case 54 side as shown in FIG. You can't insert the bolt. Even if the front lid 61 is rotated, the deviation is not eliminated. Therefore, it is possible to prevent a wrong assembly such that the front and back are mistaken.

  When the front lid 61 is rotated 90 ° to the right or left with respect to the normal orientation, the bolt holes 59a to 59d are bolt holes 52, 53 on the case 54 side, as shown in FIG. The bolt cannot be inserted. If the front lid 61 is rotated, the deviation can be eliminated. Therefore, it is possible to prevent an erroneous assembly that has been accidentally rotated by 90 °.

Next, the operation of the two positioning hollow pins 34 shown in FIG. 8 will be described with reference to FIG. 11, which is a sectional view taken along the line 11-11 in FIG.
As shown in FIG. 11, the positioning hollow pin 34 is inserted into the first female screw hole 26. Next, the lower ends of the bolt holes 62 of the bottom lid 66 and the bolt holes 52 of the case 54 are fitted into the upper half of the positioning hollow pin 34. Next, the front lid 61 is placed on the case 54, and in this state, the bolt 28 is screwed into the first female screw hole 26.
As shown in FIG. 8, the two positioning hollow pins 34, 34 are arranged diagonally so that the case 54 is positioned with respect to the base plate 25 in the paper surface direction (perpendicular to the motor shaft 21) in FIG. 8. Is made accurately.

Next, the structure of the exhaust chamber will be described with reference to FIG. 12, which is an enlarged view of the main part of FIG.
As shown in FIG. 12, the upper surface of the partition part 88 constituting the floor of the first exhaust chamber 97 has a stepped shape including an upper step part 88 a and a lower step part 88 b. A first through hole 85 that connects the first exhaust chamber 97 and the second exhaust chamber 98 is provided in the upper step portion 88a, and a first connection portion that connects the first exhaust chamber 97 and the second exhaust chamber 98 to the lower step portion 88b. Two through holes 86 and a third through hole 87 are provided.

The first through-hole 85, the second through-hole 86, and the third through-hole 87 have different levels of upper openings. That is, the second through hole 86 is higher than the third through hole 87 by Δh1. Further, the first through hole 85 is higher than the third through hole 87 by Δh2 (Δh1 <Δh2).
In addition, the out groove 65 provided in the bottom cover 66 is disposed at the lowest position of the bottom cover 66.

Even if outside water enters the second exhaust chamber 98 from the final exhaust port 81, it takes time until the first exhaust chamber 97 is submerged because the first exhaust chamber 97 is above the second exhaust chamber 98. Can earn.
Even if water enters the first exhaust chamber 97, first, the third through hole 87 is closed, but the first through hole 85 and the second through hole 86 are kept open, so that negative pressure is maintained. Pump exhaust performance is maintained.
Furthermore, even if the second through-hole 86 is blocked with water, the first through-hole 85 is kept open, so that the exhaust performance of the negative pressure pump is maintained.

  In addition, when the negative pressure pump is stopped, the lower part of the negative pressure pump accumulates and is immersed in water, so that even if water enters the case 54, the water that has entered the case 54 has the lowest level. It is quickly discharged through the pump-out hole 64 and the out-groove 65 arranged at the position. At this time, the final exhaust port 81 functions as a drain for discharging the invading water.

Next, the structure and operation of the check valve 100 will be described.
As shown in FIG. 13, the check valve 100 includes an umbrella-shaped valve body 102 having a needle 101, a valve seat portion 104 that closes the flow path 103 when the valve body 102 is lifted and covered, and the valve seat It comprises a valve box 105 that integrally has a portion 104 and accommodates the valve body 102 in a movable manner. The valve box 105 includes a box base 107 having a sealing material 106 and a case 109 having a through hole 108 and movably storing the valve body 102 and fitted into the box base 107. Yes.
The valve body 102 is urged in the valve closing direction by the return spring 102a when the negative pressure pump is operated.

  During operation of the negative pressure pump, the inlet of the pump unit 50 is at a lower pressure than the hose plug 42. With this pressure difference, as shown in FIG. 13, the valve body 102 is separated from the valve seat portion 104 against the biasing force of the return spring 102a, and the check valve 100 is opened. Then, air is sucked in as indicated by an arrow (7). The sucked air is filtered by the filter 35. The air passes through the check valve 100 as indicated by an arrow (8), passes through the check valve 100, and enters the pump unit 50 from the pump-in hole 60 as indicated by an arrow (9).

  Pressurized by the pump unit 50 and reaches the second exhaust chamber 98 through the pump-out hole 64, the out groove 65, and the first exhaust chamber 97 as indicated by the arrow (10), and as indicated by the arrow (11). The air is discharged from the final exhaust ports 81 and 81 to the outside.

Next, the state when the motor 22 is stopped (when the negative pressure pump is stopped) will be described with reference to FIG.
Here, a closed space between the check valve 100 and the pump unit 50 (corresponding to a space surrounded by the outer surface of the front lid 61 and the inner surface of the cover unit 70) is referred to as a suction chamber 110. The volume of the suction chamber 110 is V1.
For convenience, the pump unit 50 is divided into two, and the volume on the front lid 61 side is set to V2, and the volume on the bottom lid 66 side is set to V3. Further, the volume of the first exhaust chamber 97 is V4, and the volume of the second exhaust chamber 98 is V5.

When the motor 22 is stopped, the check valve 100 is closed as shown in FIG. In a state immediately before the motor 22 stops, the volume V1 and volume V2 areas are negative pressure areas, and the volume V3 to V5 areas are positive pressure areas. This balance is lost at the moment when the motor 22 stops.
That is, air is supplied from the region of the volumes V3 to V5 to the region of the volumes V1 to V2, and all regions change so as to return to atmospheric pressure.

In the present invention, the sizes of the suction chamber 110 and the second exhaust chamber 98 are set so that the relationship of volume V1 <volume V5 is maintained. Volume V2 and volume V3 are equal.
As the motor 22 stops, the air moves. However, since (V1 + V2) <(V3 + V5), surplus is generated in the volume V5.

  As a result, even if external moisture-containing air flows back to the second exhaust chamber 98, it is only mixed with excess air in the second exhaust chamber 98, and the moisture-containing air is absorbed into the pump chamber 50 and the suction chamber. There is no need to worry about entering the chamber 110.

Next, as described with reference to FIG. 6, the final exhaust port 81 is provided on the same end surface of the four corners of the second exhaust chamber 98 having a rectangular cross section surrounded by the four exhaust chamber walls 73. The operation due to the provision of the four final exhaust ports 81 will be described with reference to FIG.
FIG. 15B is a front view of the negative pressure pump 10, and the negative pressure pump 10 may rotate (roll) as indicated by an arrow (20). At this time, the final exhaust ports 81L and 81L (L is a subscript indicating the left) shown in FIG. As a result, moisture is discharged from the final exhaust ports 81R and 81R (R is a subscript indicating right) shown in FIG. 15C, which is a right side view, and the final exhaust ports 81L and 81R in FIG. The exhaust continues from 81L.

Further, the negative pressure pump 10 may rotate as indicated by an arrow (21) shown in FIG. At this time, of the two final exhaust ports 81L and 81L, the final exhaust port 81L closer to the motor 22 is positioned higher, and the exhaust is continued from here and the moisture is discharged from the other final exhaust port.
Thus, by skillfully arranging the four final exhaust ports 81, exhaust can be continued even if the negative pressure pump 10 is tilted.

The present invention described above can be summarized as follows.
First, as shown in FIG. 13, the present invention includes a plurality of exhaust chambers 97 and 98 on the outlet side of the pump unit 50, and the plurality of exhaust chambers 97 and 98 are connected in series through through holes 85 to 97. A negative pressure pump,
The plurality of exhaust chambers 97, 98 are adjacent to a second exhaust chamber 98 having a final exhaust port for exhausting air to the outside, and a partition 88 on the outlet side of the pump unit 50 from the second exhaust chamber 98. And a first exhaust chamber 97 provided, and a final exhaust port 81 for discharging air to the second exhaust chamber 98 to the outside. Alternatively, as shown in FIG. 16, a plurality of through holes 85 to 87 that communicate the first exhaust chamber 97 and the second exhaust chamber 98 are provided, and the plurality of through holes 85 to 87 are provided on one side. The height difference Δh2 is provided so that the other through-hole 85 is higher than the upper end of the through-hole 87, and the other through-hole 86 is higher than the upper end of one through-hole 87. A height difference Δh1 is provided.

  Even if water enters the second exhaust chamber 98 from the outside and this water further enters the first exhaust chamber 97 closer to the pump unit 50 through the through hole, the higher through hole 85 (the other through hole) Since the hole) is not blocked, air can flow through the other through-hole 85, and the exhaust action of the exhaust pump can be maintained. That is, according to the present invention, it is possible to delay the flooding into the pump unit 50 and to suppress the entry of water or the like into the pump unit 50.

  Further, water or the like accumulated on the upper surface of the partition portion 88 can be smoothly dropped into the second exhaust chamber 98 through the lower through hole 87 (one through hole) and discharged to the outside through the final exhaust port 81. .

Preferably, the upper surface of the partition portion 88 has a stepped shape, and the through holes 87, 86, and 85 are provided in the lower step portion 88b and the upper step portion 88a, respectively.
It is only necessary to make holes in the lower and upper steps, and through holes having different upper surface heights can be easily formed.

Next, a modified example of FIG. 12 will be described.
As shown in FIG. 16, the upper surface of the partition part 88 is not provided with a step. Instead, the first tube 118 that is sufficiently longer than the thickness of the partition portion 88 is driven from below to form the first through hole 85, and the second tube is shorter than the first tube 118 but longer than the thickness of the partition portion 88. The second through hole 85 is formed by driving 119 from below. For other elements, the reference numerals in FIG. 12 are used, and the description is omitted.
Compared to FIG. 12, the upper surface of the partition portion 88 is apparently flat (exactly curved in the direction of the front and back of the drawing), so that the volume of the first exhaust chamber 97 can be gained, Since no step is provided, the molding die cost and machining cost can be reduced.

In this embodiment, the height of the through hole is 3, but it may be 2 or 4 or more.
In this embodiment, the exhaust chamber is composed of the first exhaust chamber and the second exhaust chamber, but may be three (three chambers) or more.

Furthermore, although the present Example demonstrated the vane pump as a negative pressure pump, a negative pressure pump is not restricted to a vane pump.
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, 50 ... Pump part, 81 ... Final exhaust port, 85 ... 1st through-hole, 87 ... 3rd through-hole, 88 ... Partition part, 88a ... Upper stage part, 88b ... Lower stage part, 97 ... 1st Negative pressure chamber, 98 ... second negative pressure chamber.

Claims (2)

A negative pressure pump provided with a plurality of exhaust chambers on the outlet side of the pump unit, wherein the plurality of exhaust chambers are connected in series with through holes,
The plurality of exhaust chambers include a second exhaust chamber having at least a final exhaust port for exhausting air to the outside, and a first exhaust gas adjacent to the second exhaust chamber on the outlet side of the pump unit by a partitioning portion. An exhaust chamber,
The negative pressure pump, wherein the plurality of through holes are provided with a difference in height so that the other through hole is higher than an upper end of the one through hole. The negative pressure pump according to claim 1,
The negative pressure pump according to claim 1, wherein an upper surface of the partition portion has a stepped shape, and the through holes are respectively provided in the lower step portion and the upper step portion.

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