JP2010236506A - Vane pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vane pump which is unlikely to be assembled erroneously. <P>SOLUTION: At least one tightening member 59a and the other tightening member 59b adjacent to the tightening member 59a are disposed so that the distance therebetween is different from the distance between the remaining tightening members (such as 59b and 59c) as shown in Fig.(a). Therefore, when a front cover 61 is applied to a case 54 upside down, as shown in Fig.(b), all bolt holes 59a-59d are displaced from bolt holes 52, 53 on the case 54 side, and bolts cannot be inserted into the bolt holes. When the front cover 61 is rotated 90° clockwise or counterclockwise relative to the normal direction, as shown in Fig.(c), the bolt holes 59a-59d are displaced from the bolt holes 52, 53 on the case 54 side, and the bolts cannot be inserted into the bolt holes. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

FIG. 16 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 tube 215 extending from a negative pressure chamber 214 of the negative pressure booster 213, and a tip of the negative pressure tube 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. 17 is an exploded perspective view of a conventional negative pressure pump. A vane pump type negative pressure pump 250 is mounted on a mount plate 253 having an inlet pipe 251 and legs 252 and on one surface of the mount plate 253. The motor 256 includes a power supply cable 254 and a round bar-shaped motor shaft 255, a cup 257 attached to the other surface of the mount plate 253, and a pump unit 258 surrounded by the cup 257.

  The pump unit 258 includes a rotor 260 with a vane 259, a case 261 that rotatably houses the rotor 260, a first lid 262 and a second lid 263 that respectively block both sides of the case 261, and a second lid 263. And a bolt 264 fixed to the mount plate 253 in a state where the case 261 and the first lid 262 are overlapped.

  Considering ease of sealing and weight reduction, as shown in the figure, the first lid 262 and the second lid 263 have a simple disk shape. In addition, due to machining, the plurality of bolt holes 265 are arranged at an equal pitch (in the case of three, 120 ° pitch). As a result, the manufacturing cost of the pump unit 258 can be reduced.

On the other hand, the first lid 262 and the second lid 263 increase the possibility that the front and back will be wrong or the mounting angle will be wrong during assembly. That is, as a price for simplifying the structure, misassembly is likely to occur.
Further, although it is possible to prevent misassembly of the first lid 262 and the second lid 263 and the case 261 by concave / convex fitting, there is a problem in workability because the concave / convex processing is necessary.
Thus, since the state of the pump part 258 becomes invisible when covered with the cup 257, a countermeasure for preventing misassembly is desired.

US Pat. No. 6,491,505

  It is an object of the present invention to provide a vane pump that is unlikely to be misassembled.

The invention according to claim 1 includes a plurality of vanes, a rotor that supports these vanes, a case that rotatably stores the rotor, a front lid and a bottom lid that close both ends of the case, and the front lid A vane pump comprising a plurality of fastening members fastened to a base plate in a state where the case and the bottom lid are overlapped,
The distance between at least one fastening member and another fastening member adjacent to the fastening member is arranged to be different from the distance between the remaining fastening members.

  According to the first aspect of the present invention, if the front lid is applied to the case with the front and back reversed, the positions of all the fastening members are shifted from the fastened parts on the case side, and the fastening members are Can't install. Even if the front lid is rotated, the deviation is not resolved. Therefore, it is possible to prevent a wrong assembly such that the front and back are mistaken. The same applies to the bottom lid.

In addition, even when the front lid is rotated 90 ° to the right or left with respect to the normal orientation, the position of the fastening member is shifted from the portion to be fastened on the case side, and the fastening member cannot be attached.
Thus, according to the present invention, it is possible to prevent erroneous assembly. The same applies to the bottom lid.

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 is a figure explaining the structure of a 2nd 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 bolt hole. 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 principle diagram of a conventional booster brake device. It is a disassembled perspective view of the conventional negative pressure pump.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The vane pump of the present invention can be used for either a negative pressure pump or a positive pressure pump. Moreover, if it is a negative pressure pump, it is suitable for the negative pressure booster for vehicles, but the use is arbitrary.

  Hereinafter, the vane pump of the present invention will be described taking a negative pressure pump as an example. Further, the fastening member described in the claims will be described by taking a bolt as an example.

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 stepped on 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. 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 a 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 portion 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 is detachably inserted into an inlet portion 72 of the cover portion 70. 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 cover 66 is provided with an out groove 65 radially outward from the pump-out hole 64, and the rotor 57 and the 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 portion 40 is detachably provided by being inserted into the inlet portion 72 of the cover portion 70 from above, and the check valve 100 is stored in the inlet portion 72 of the cover portion 70 in the connecting portion 40. 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, the first exhaust chamber 97 is located above the second exhaust chamber 98, so it takes time until the first exhaust chamber 97 is submerged. 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 closed 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 soaked 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 shown by an arrow (8), passes through the check valve 100, and enters the pump unit 50 from the pump-in hole 60 as shown 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 ports 81 are 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 effect of providing 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 the right) shown in FIG. 15C, which is the right side view, and the final exhaust ports 81L and 81R in FIG. 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.
As shown in FIG. 3, the present invention includes a plurality of vanes 58, a rotor 57 that supports these vanes 58, a case 54 that rotatably stores the rotor 57, and both ends (both openings) of the case 54. And a plurality of fastening members (for example, bolts) that fasten the front lid 61, the case 54, and the bottom lid 66 to the base plate (reference numeral 25). A vane pump 10 comprising 28,
As shown in FIG. 10A, the interval between at least one fastening member 59a and another fastening member 59b adjacent to the fastening member 59a is different from the remaining fastening member (for example, the interval between 59b and 59c). It is arranged.

  As shown in FIG. 10B, when the front lid 61 is applied to the case with the front and back reversed, the positions 59a to 59d of all the fastening members are shifted from the fastened portions 52 and 53 on the case side. Therefore, the fastening member cannot be attached. Even if the front lid is rotated, the deviation is not resolved. Therefore, it is possible to prevent a wrong assembly such that the front and back are mistaken. The same applies to the bottom lid.

Further, as shown in FIG. 10C, even when the front lid 61 is rotated 90 ° to the right or left with respect to the normal orientation, the positions 59a to 59d of the fastening members are to be fastened on the case side. 52 and 53, and a fastening member cannot be attached.
Thus, according to the present invention, it is possible to prevent erroneous assembly. The same applies to the bottom lid.
Thus, according to the present invention, it is possible to prevent erroneous assembly.

In this embodiment, the fastening member is a bolt, but other fastening members may be used.
Moreover, although the number of fastening members was four, it may be three or five or more.
Furthermore, the vane pump of the present invention is suitable for a negative pressure pump for a vehicle for making the negative pressure chamber of the negative pressure booster provided in the vehicle negative pressure, but the application is not particularly limited, It can be applied to machines, general-purpose machines, and general equipment. The vane pump can be used for either a negative pressure pump or a positive pressure pump.

  The vane 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.

  DESCRIPTION OF SYMBOLS 10 ... Vane pump (negative pressure pump), 25 ... Base plate, 28 ... Fastening member (bolt), 52, 59 ... Bolt hole, 54 ... Case, 57 ... Rotor, 58 ... Vane, 61 ... Front lid, 66 ... Bottom lid

Claims (1)

A plurality of vanes, a rotor that supports these vanes, a case that rotatably stores the rotor, a front lid and a bottom lid that close both ends of the case, and the front lid, the case, and the bottom lid A vane pump comprising a plurality of fastening members fastened to the base plate in a stacked state,
A vane pump characterized in that an interval between at least one fastening member and another fastening member adjacent to the fastening member is different from a spacing between the remaining fastening members.

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