Mounting structure for pump

Abstract

To enhance mounting accuracy of a pump to a mounted body inexpensively.SOLUTION: In a mounting structure 100 for mounting a housing 2 of a pump (electric pump 101) to a mounted body 102 via a mounting bolt 40, the housing 2 includes: a through hole 31 through which the mounting bolt 40 is inserted; and a port opening on an outer surface of the housing 2. The mounted body 102 includes: a fastening hole 50 that is formed corresponding to the through hole 31 of the housing 2 and to which the mounting bolt 40 is fastened; and an opening part 52 with which the port of the housing 2 communicates. The mounting structure 100 includes: a collar 41 that is provided to be inserted through the through hole 31 and in which the mounting bolt 40 is inserted through a hollow part 41a; and an insertion hole 53 that is provided coaxially with the fastening hole 50 and into which a tip part 41b of the collar 41 is inserted. The collar 41 includes a large diameter part 41d formed in a base end part and sandwiched between a head part 40a of the mounting bolt 40 and the housing 2.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a mounting structure of a pump.

Background Art

[0002] Patent Document 1 discloses a mounting structure of an electric pump device, which includes the electric pump device and an object to be mounted on which the electric pump device is mounted. In this mounting structure, the positioning portion of the electric pump device is fitted with the positioning portion of the mounting surface of the object to be mounted, thereby ensuring the mounting accuracy of the electric pump device with respect to the object to be mounted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, the positioning portion of the electric pump device is a pin portion that is fixed by press-fitting into a hole formed in the end face of the flange portion. Therefore, a dedicated hole into which the pin portion is press-fitted is required, resulting in an increase in the manufacturing cost of the electric pump.

[0005] The present invention has been made in view of the above problems, and an object thereof is to enhance the mounting accuracy of the pump with respect to the object to be mounted at low cost.

Means for Solving the Problems

[0006] The present invention relates to an attachment structure for attaching a pump housing to an object to be attached via a fastening member. The housing has a through-hole through which the fastening member is inserted and a port that opens to the outer surface of the housing. The object to be attached has a fastening hole formed corresponding to the through-hole of the housing and to which the fastening member is fastened, and an opening that communicates with the port of the housing. The port is a suction port for guiding liquid to the pump or a discharge port for guiding the liquid discharged from the pump. The attachment structure includes a cylindrical member provided through the through-hole and having a hollow portion through which the fastening member is inserted, and an insertion hole provided coaxially with the fastening hole and into which the tip of the cylindrical member is inserted. The cylindrical member is provided across the through-hole of the housing and the insertion hole of the object to be attached, thereby positioning the housing with respect to the object to be attached. The cylindrical member is characterized by having a large-diameter portion formed at the base end and sandwiched between the head of the fastening member and the housing.

[0007] In this invention, the insertion hole provided with the cylindrical member for positioning the housing with respect to the object to be attached is provided in the fastening hole to which the fastening member for attaching the housing to the object to be attached is fastened. Further, both the fastening member and the cylindrical member are provided in the through-hole of the housing. Thus, the fastening member and the cylindrical member having different functions are provided at a common position. Therefore, the attachment accuracy of the pump to the object to be attached can be improved at low cost.

[0008] Further, the present invention is characterized in that the cylindrical member further has a press-fitting portion at least partially formed to have a diameter larger than the inner diameters of the through-hole and the insertion hole.

[0009] In this invention, by managing the position of the press-fitting portion and press-fitting the cylindrical member across the through-hole and the insertion hole, the positioning of the housing with respect to the object to be attached can be made accurate.

[0010] Further, the present invention is characterized in that the press-fitting portion is formed in a tapered shape in which the outer diameter increases toward the base end of the cylindrical member.

[0011] In the present invention, in the process of press-fitting the cylindrical member into the through-hole and the insertion hole, the through-hole and the insertion hole can be easily arranged coaxially.

[0012] Further, in the present invention, the housing further has a housing hole formed in the through-hole and accommodating at least a part of the large-diameter portion of the cylindrical member, and the outer peripheral surface of the large-diameter portion of the cylindrical member contacts the inner peripheral surface of the housing hole, and the outer peripheral surface of the tip portion contacts the inner peripheral surface of the insertion hole, whereby the housing is positioned with respect to the attached body.

[0013] In the present invention, since high machining accuracy is not required for the inner peripheral surface of the through-hole, the machining of the housing becomes easy.

[0014] Further, in the present invention, the large-diameter portion of the cylindrical member is formed by being plastically deformed by the head of the fastening member in the process of fastening the fastening member to the fastening hole.

[0015] In the present invention, the cylindrical member can have a simple structure.

Effect of the Invention

[0016] According to the present invention, the mounting accuracy of the pump with respect to the attached body can be improved at low cost.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0018] Hereinafter, with reference to the drawings, the mounting structure 100 according to the embodiment of the present invention will be described. The mounting structure 100 is for attaching the electric pump 101 to the attached body 102 via a mounting bolt 40 as a fastening member.

[0019] The electric pump 101 is mounted on, for example, a vehicle and discharges a coolant (liquid) for cooling an electric motor mounted on the vehicle or discharges an oil (liquid) for lubricating a gear mounted on the vehicle. The electric pump 101 may be used as a fluid pressure supply source for discharging a working fluid (liquid) for driving a device. Further, the electric pump 101 may be mounted on industrial machinery other than vehicles.

[0020] First, with reference to FIGS. 1 and 2, the electric pump 101 and the attached body 102 will be described. FIG. 1 is a side view of the state where the electric pump 101 is attached to the attached body 102, and the attached body 102 is shown in cross section. FIG. 2 is a perspective view of the electric pump 101 alone.

[0021] As shown in FIGS. 1 and 2, the electric pump 101 has a housing 2 that houses a pump section and a motor section connected via a drive shaft (not shown). The housing 2 also houses a controller that controls the drive of the motor section. In this way, the electric pump 101 is a unit in which the pump section, the motor section, and the controller are housed in the housing 2. The drive shaft is rotatably supported by the housing 2 via bearings. In the present embodiment, the pump section is an internal gear pump having an inner rotor connected to the drive shaft and an outer rotor disposed outside the inner rotor. Since the configuration of the internal gear pump is the same as a well-known configuration, a detailed description thereof will be omitted. Note that the pump section is not limited to an internal gear pump, and other pumps such as other gear pumps and vane pumps may be used.

[0022] The housing 2 has a main body portion 10 and a cover portion 20 that is fixed to the main body portion 10 via fixing bolts 3 and seals the opening of the main body portion 10. Hereinafter, the axial direction of the drive shaft will also be simply referred to as the "axial direction".

[0023] The main body portion 10 has a rectangular portion 11 with a rectangular outer periphery and a circular portion 12 formed integrally with the rectangular portion 11 and having a circular outer periphery. The pump section is housed in a first circular portion 12a on the tip side of the circular portion 12, and the motor section is housed in a second circular portion 12b on the base end side of the circular portion 12. The controller is housed in the rectangular portion 11. The cover portion 20 has a disk portion 21 having the same outer diameter as the outer diameter of the circular portion 12 and attached to the end face of the circular portion 12, and a protruding portion 22 formed to protrude from the disk portion 21. The protruding portion 22 protrudes parallel to the axial direction of the drive shaft, and the central axis of the protruding portion 22 is offset from the central axis of the drive shaft.

[0024] On the surface of the disk portion 21, a suction port 21a (see FIG. 1) for guiding liquid to the pump section is provided. Also, on the tip surface of the protruding portion 22, a discharge port 22a (see FIG. 1) for guiding the liquid discharged from the pump section to the outside is provided. The suction port 21a and the discharge port 22a open to the outer surface of the housing 2. In FIG. 1, the suction port 21a and the discharge port 22a are shown by dotted lines.

[0025] In the main body portion 10, the dimension of the rectangular portion 11 in the direction perpendicular to the drive shaft is larger than the outer diameter of the circular portion 12. Therefore, an end face 11a that extends radially from the outer peripheral surface of the circular portion 12 is formed on the rectangular portion 11. By abutting the end face 11a against the end face 102a of the attached body 102, it has the function of determining the axial position of the electric pump 101 with respect to the attached body 102.

[0026] A plurality of flanges 30 are formed on the outer peripheral surface of the rectangular portion 11. The end face 30a of the flange 30 and the end face 11a of the rectangular portion 11 are formed as a continuous surface. A through hole 31 through which a mounting bolt 40 for fixing the electric pump 101 to the attached body 102 is inserted is formed in the flange 30.

[0027] The attached body 102 is a case of a device that utilizes the liquid discharged from the electric pump 101. The device is, for example, a transmission or a transaxle device.

[0028] As shown in FIG. 1, the attached body 102 is formed corresponding to the through hole 31 of the housing 2 of the electric pump 101, and has a fastening hole 50 (see FIG. 3) to which the mounting bolt 40 is fastened, a housing recess 51 that houses a part of the housing 2, and an opening 52 formed on the bottom surface of the housing recess 51 into which the protruding portion 22 of the housing 2 is inserted. The through hole 31 and the fastening hole 50 are formed coaxially. The fastening hole 50 and the housing recess 51 are formed to open to the end face 102a of the attached body 102. An internal thread into which the male thread of the mounting bolt 40 is screwed is formed on the inner peripheral surface of the fastening hole 50.

[0029] When attaching the electric pump 101 to the object to be attached 102, the circular portion 12 of the housing 2 of the electric pump 101 is accommodated in the accommodation recess 51 of the object to be attached 102. While the end face 11a of the rectangular portion 11 of the housing 2 is brought into contact with the end face 102a of the object to be attached 102, the protruding portion 22 of the housing 2 is inserted into the opening 52 of the object to be attached 102. Then, the mounting bolt 40 is inserted through the through hole 31 of the housing 2 and fastened to the fastening hole 50 of the object to be attached 102, thereby pressing the end face 11a of the rectangular portion 11 of the housing 2 and the end face 30a of the flange 30 against the end face 102a of the object to be attached 102, and attaching the electric pump 101 to the object to be attached 102. In a state where the electric pump 101 is attached to the object to be attached 102, the space between the housing 2 and the bottom surface of the accommodation recess 51 of the object to be attached 102, specifically, the space between the cover portion 20 and the bottom surface of the accommodation recess 51 becomes the storage portion 4 where the liquid is stored. The suction port 21a provided on the surface of the disk portion 21 of the cover portion 20 faces the storage portion 4. Also, in a state where the electric pump 101 is attached to the object to be attached 102, the discharge port 22a formed on the tip end face of the protruding portion 22 communicates with the opening 52.

[0030] When the motor portion of the electric pump 101 is driven in a state where the electric pump 101 is attached to the object to be attached 102, the pump portion of the electric pump 101 sucks the liquid from the storage portion 4 through the suction port 21a, pressurizes the liquid, and discharges the pressurized liquid to be led to the opening 52 of the object to be attached 102 through the discharge port 22a.

[0031] There is a slight gap between the outer peripheral surface of the circular portion 12 of the housing 2 and the inner peripheral surface of the accommodation recess 51. Also, there is a slight gap between the outer peripheral surface of the protruding portion 22 of the housing 2 and the inner peripheral surface of the opening 52. An O-ring 5 as a seal member is provided on the outer peripheral surface of the protruding portion 22, and the O-ring 5 is compressed between the outer peripheral surface of the protruding portion 22 and the inner peripheral surface of the opening 52 to seal between the two. Therefore, the liquid guided to the opening 52 through the discharge port 22a of the protruding portion 22 is prevented from leaking into the accommodation recess 51 through the gap between the protruding portion 22 and the opening 52, and is supplied to the device through the opening 52. That is, the O-ring 5 prevents the discharge side and the suction side of the pump section from communicating with each other, and prevents the performance of the pump section from deteriorating. An O-ring (not shown) as a seal member for sealing between the two is also provided between the end surface 11a of the rectangular portion 11 of the housing 2 and the end surface 102a of the attached body 102.

[0032] Here, when the electric pump 101 is fixed to the attached body 102 only by the mounting bolts 40, there are gaps between the outer peripheral surface of the circular portion 12 of the housing 2 and the inner peripheral surface of the accommodation recess 51, and between the outer peripheral surface of the protruding portion 22 of the housing 2 and the inner peripheral surface of the opening 52. Therefore, the protruding portion 22 may be inserted into the opening 52 with its central axis displaced from the central axis of the opening 52. In that case, the compression amount of the O-ring 5 will not be uniform in the circumferential direction, and the sealing performance of the O-ring 5 will be impaired.

[0033] Therefore, in the present embodiment, in order to improve the mounting accuracy of the electric pump 101 with respect to the attached body 102, specifically, in order to improve the positioning accuracy of the protruding portion 22 with respect to the opening 52, the mounting structure 100 has the following configuration. FIG. 3 is a cross-sectional view of the mounting structure 100, where (a) shows a state where the mounting bolt 40 is not fastened to the fastening hole 50, and (b) shows a state where the mounting bolt 40 is fastened to the fastening hole 50.

[0034] As shown in FIG. 3, the mounting structure 100 includes a collar 41 provided by inserting through a through hole 31, which is a cylindrical member through which a mounting bolt 40 is inserted into a hollow portion 41a, and an insertion hole 53 provided coaxially with a fastening hole 50 and into which a tip portion 41b of the collar 41 is inserted.

[0035] The insertion hole 53 is provided to open at an end face 102a and is provided coaxially with the fastening hole 50. The inner diameter of the insertion hole 53 is formed to be larger than the inner diameter of the fastening hole 50 and is formed to be substantially the same as the inner diameter of the through hole 31.

[0036] In this embodiment, the collar 41 is made of metal, but the collar 41 is not limited to being made of metal. The collar 41 is provided across the through hole 31 and the insertion hole 53 (in other words, provided across the housing 2 of the electric pump 101 and the object 102 to be mounted), and is for positioning the housing 2 with respect to the object 102 to be mounted. The collar 41 has a cylindrical main body portion 41c and a large-diameter portion 41d formed at a base end portion. The collar 41 is provided such that the main body portion 41c is inserted into the through hole 31 and the insertion hole 53, and the large-diameter portion 41d contacts the surface 30b of the flange 30.

[0037] The outer diameter of the main body portion 41c is formed to be substantially the same as the inner diameters of the through hole 31 and the insertion hole 53, and the inner diameter is formed to be larger than the outer diameter of the mounting bolt 40. The axial length of the main body portion 41c is longer than the axial length of the through hole 31 and is smaller than the sum of the axial lengths of the through hole 31 and the insertion hole 53. Therefore, the tip portion 41b of the collar 41 is positioned within the insertion hole 53 and does not contact the bottom surface of the insertion hole 53. In a state where the collar 41 is inserted into the through hole 31 and the insertion hole 53, the outer peripheral surface of the main body portion 41c contacts the inner peripheral surfaces of the through hole 31 and the insertion hole 53. In other words, the outer peripheral surface of the main body portion 41c fits into the inner peripheral surfaces of the through hole 31 and the insertion hole 53. By providing the collar 41 across the housing 2 and the object 102 to be mounted in this way, the housing 2 is positioned with respect to the object 102 to be mounted.

[0038] The large-diameter portion 41d is formed to have a larger diameter than the head 40a of the mounting bolt 40. When the mounting bolt 40 is fastened to the fastening hole 50, as shown in Fig. 3(b), the large-diameter portion 41d is sandwiched between the head 40a of the mounting bolt 40 and the housing 2. In other words, the large-diameter portion 41d functions as a seating surface of the mounting bolt 40. Therefore, the large-diameter portion 41d can secure the area of the seating surface of the mounting bolt 40.

[0039] To attach the electric pump 101 to the object to be attached 102, while housing the circular portion 12 of the housing 2 in the housing recess 51 of the object to be attached 102 and inserting the protruding portion 22 of the housing 2 into the opening 52 of the object to be attached 102, the positions of the through hole 31 and the insertion hole 53 are aligned, and the collar 41 is inserted into the through hole 31 and the insertion hole 53. By attaching the electric pump 101 to the object to be attached 102 via the collar 41, the attachment accuracy of the electric pump 101 to the object to be attached 102 is improved, so the positioning accuracy of the protruding portion 22 with respect to the opening 52 is improved. As a result, the central axis of the protruding portion 22 and the central axis of the opening 52 coincide, and the compression amount of the O-ring 5 becomes uniform in the circumferential direction, so the sealing performance of the O-ring 5 becomes good. After attaching the electric pump 101 to the object to be attached 102 via the collar 41, the electric pump 101 is fixed to the object to be attached 102 using the mounting bolt 40.

[0040] Thus, in the mounting structure 100, the insertion hole 53 provided with the collar 41 for positioning the housing 2 with respect to the object to be attached 102 is provided in the fastening hole 50 to which the mounting bolt 40 for attaching the housing 2 to the object to be attached 102 is fastened. Also, both the mounting bolt 40 and the collar 41 are provided in the through hole 31 of the housing 2. Thus, in the mounting structure 100, the mounting bolt 40 and the collar 41 having different functions are provided at a common position. Therefore, compared with the case where the mounting bolt 40 and the collar 41 are provided at different positions, the attachment accuracy of the electric pump 101 to the object to be attached 102 can be increased at low cost.

[0041] In the mounting structure 100, the insertion hole 53 is formed coaxially with the fastening hole 50. Therefore, the processing of the insertion hole 53 can be carried out together with the processing of the fastening hole 50. In other words, the processing of the insertion hole 53 and the fastening hole 50 with different functions can be carried out together. Thus, compared with the case where the insertion hole 53 and the fastening hole 50 are processed separately at different positions, the processing man-hours can be reduced and the processing accuracy can be improved.

[0042] Also, Fig. 8 shows a mounting structure 200 as a comparative example of the present embodiment, in which a cylindrical collar 141 having no large-diameter portion 41d is provided across the insertion hole 53 and the collar hole 132 of the flange 30. In the mounting structure 200, in the flange 30, instead of the through-hole 31, a bolt hole 131 that opens on the surface 30b and through which the mounting bolt 40 is inserted, and a collar hole 132 that opens on the end surface 30a and is provided coaxially with the bolt hole 131 are formed. The inner diameter of the collar hole 132 is formed to be larger than the inner diameter of the bolt hole 131 and substantially the same as the inner diameter of the insertion hole 53. In this way, the collar 141 is provided in the collar hole 132 that is not a through-hole.

[0043] In the mounting structure 200, to mount the electric pump 101 on the object to be mounted 102, the collar 141 is fixed in the collar hole 132 by press-fitting in advance, and then while the circular portion 12 of the housing 2 is accommodated in the accommodation recess 51 of the object to be mounted 102, the protruding portion 22 of the housing 2 is inserted into the opening 52 of the object to be mounted 102, and the collar 141 is press-fitted into the insertion hole 53 of the object to be mounted 102. At this time, since the collar 141 press-fitted into the collar hole 132 of the flange 30 must be press-fitted perpendicularly to the end surface 102a, it is troublesome to mount the electric pump 101. On the other hand, in the mounting structure 100 of the present embodiment, it is not necessary to provide the collar 41 in the through-hole 31 and the insertion hole 53 in advance at the time of mounting. After the protruding portion 22 of the housing 2 is inserted into the opening 52 of the object to be mounted 102, the collar 41 can be easily mounted through the through-hole 31. Therefore, compared with the mounting structure 200, the assembly becomes easier.

[0044] In addition, in the mounting structure 100 and Comparative Example 200, it is necessary to control the protrusion amount of the collar 41, 141 (in other words, the length by which the collar 41, 141 protrudes into the insertion hole 53) so that the collar 41, 141 does not contact the bottom surface of the insertion hole 53. In the mounting structure 200 of the comparative example, since the collar 141 is press-fitted into the collar hole 132, a slight gap is formed between the bottom surface of the collar hole 132 and the collar 141. Since the protrusion amount of the collar 141 changes depending on the amount of this gap, it is difficult to control the protrusion amount of the collar 141. On the other hand, in the mounting structure 100 of the present embodiment, the large-diameter portion 41d formed at the base end portion of the collar 41 is fixed by the mounting bolt 40. Therefore, the protrusion amount of the collar 41 is determined only by the thickness of the flange 30 (in other words, the axial length of the through hole 31) and the axial length of the collar 41. Therefore, it is easy to control the protrusion amount of the collar 41.

[0045] In addition, in the present embodiment, as shown in FIG. 2, a plurality of through holes 31 are formed. The collar 41 is preferably provided in all of the plurality of through holes 31, but may be provided only in a specific through hole 31. Further, the through holes 31 are not limited to the configuration in which a plurality of through holes 31 are formed, and only one through hole 31 may be formed. In other words, the electric pump 101 may be attached to the attached body 102 by only one mounting bolt 40. Even with these configurations, the mounting accuracy of the electric pump 101 with respect to the attached body 102 is improved.

[0046] According to the above embodiment, the following operational effects are achieved.

[0047] In the mounting structure 100, the insertion hole 53 in which the collar 41 for positioning the housing 2 with respect to the attached body 102 is provided is provided in the fastening hole 50 to which the mounting bolt 40 for attaching the housing 2 to the attached body 102 is fastened. Further, both the mounting bolt 40 and the collar 41 are provided in the through hole 31 of the housing 2. In this way, the mounting bolt 40 and the collar 41 having different functions are provided at a common position. Therefore, compared with the case where the mounting bolt 40 and the collar 41 are provided at different positions, the mounting accuracy of the electric pump 101 with respect to the attached body 102 can be increased at low cost.

[0048] Next, a modification of the above embodiment will be described. The following modifications are also within the scope of the present invention, and it is also possible to combine the following modifications with the configuration of the above embodiment or to combine the following modifications with each other.

[0049] <Modification 1> In the above embodiment, the color 41 is provided such that the outer diameter of the main body portion 41c is formed to be substantially the same as the inner diameters of the through hole 31 and the insertion hole 53, and the outer peripheral surface of the main body portion 41c is fitted to the inner peripheral surfaces of the through hole 31 and the insertion hole 53. However, this is not limiting. When high precision is required for the attachment of the electric pump 101, the color 41 may be press-fitted into the through hole 31 and the insertion hole 53. In other words, as shown in FIG. 4, the color 41 has a press-fitting portion 41e in which at least a part thereof is formed to have a larger diameter than the inner diameters of the through hole 31 and the insertion hole 53.

[0050] Specifically, as shown in FIG. 4(a), the press-fitting portion 41e is formed in a tapered shape with an outer diameter increasing toward the base end portion (the large-diameter portion 41d side) of the collar 41. Alternatively, as shown in FIG. 4(b), the press-fitting portion 41e is formed by bulging radially outward over the entire circumference of a part of the main body portion 41c. Or, the entire main body portion 41c is formed in a cylindrical shape with a diameter larger than the inner diameters of the through-hole 31 and the insertion hole 53 (in this case, the entire main body portion 41c serves as the press-fitting portion 41e), and in this case, knurling may be performed on the press-fitting portion 41e. With these configurations, with a part of the collar 41 inserted into the through-hole 31 (specifically, in a state where the collar 41 is not press-fitted into the through-hole 31 and the press-fitting portion 41e is exposed from the through-hole 31), by fastening the mounting bolt 40 to the fastening hole 50, the collar 41 can be press-fitted into the through-hole 31 and the insertion hole 53. Also, by managing the position of the press-fitting portion 41e so that the press-fitting portion 41e is provided across the through-hole 31 and the insertion hole 53, and press-fitting the collar 41 across the through-hole 31 and the insertion hole 53, the positioning of the housing 2 with respect to the object to be attached 102 can be made accurate. Further, when the press-fitting portion 41e is formed in a tapered shape as shown in FIG. 4(a), during the process of press-fitting the collar 41 into the through-hole 31 and the insertion hole 53, the through-hole 31 and the insertion hole 53 are guided by the press-fitting portion 41e and centered so as to be positioned coaxially, so that the through-hole 31 and the insertion hole 53 can be easily arranged coaxially.

[0051] <Modification Example 2> In the above embodiment, the collar 41 is provided such that the large-diameter portion 41d contacts the surface 30b of the flange 30. However, the present invention is not limited to this. As shown in FIG. 5, the housing 2 has a housing hole 30c, at least a part of the large-diameter portion 41d of the collar 41 is housed in the housing hole 30c, and the outer peripheral surface of the large-diameter portion 41d of the collar 41 may contact the inner peripheral surface of the housing hole 30c. The housing hole 30c is formed in the through-hole 31. Specifically, the housing hole 30c is formed coaxially with the through-hole 31 on the surface 30b of the flange 30, and the inner peripheral surface contacts the outer peripheral surface of the large-diameter portion 41d over the entire circumference in the radial direction. Further, the outer peripheral surface of the tip portion 41b of the collar 41 contacts the inner peripheral surface of the insertion hole 53. When the outer peripheral surface of the large-diameter portion 41d contacts the inner peripheral surface of the housing hole 30c and the outer peripheral surface of the tip portion 41b contacts the inner peripheral surface of the insertion hole 53, the housing 2 is positioned with respect to the object to be attached 102. In this configuration, since the inner peripheral surface of the through-hole 31 is not used for positioning, high machining accuracy for positioning is not required. Therefore, the machining of the housing 2 becomes easy.

[0052] <Modification Example 3> In the above embodiment, the collar 41 has a large-diameter portion 41d formed at the base end portion in advance. However, as shown in FIG. 6, the collar 41 does not have the large-diameter portion 41d before the mounting bolt 40 is fastened to the fastening hole 50, and the large-diameter portion 41d may be formed by being plastically deformed by the head portion 40a of the mounting bolt 40 during the process of fastening the mounting bolt 40 to the fastening hole 50. In FIG. 6, (a) shows a state where the mounting bolt 40 is not fastened to the fastening hole 50, and (b) shows a state where the mounting bolt 40 is fastened to the fastening hole 50. In this case, the collar 41 may be formed of a material that is easily plastically deformed, such as resin or aluminum. As shown in FIG. 6(a), before the mounting bolt 40 is fastened to the fastening hole 50, the collar 41 has a uniform cylindrical shape having only the main body portion 41c and is provided in contact with the bottom surface of the insertion hole 53. As shown in FIG. 6(b), when the mounting bolt 40 is fastened to the fastening hole 50, the base end portion (the left side in FIG. 6) of the collar 41 is gradually crushed and deformed by the head portion 40a, spreads radially outward, and the large-diameter portion 41d is formed. Note that the base end portion of the collar 41 may be formed in a tapered shape so as to be easily plastically deformed radially outward. With this configuration, the collar 41 can be made into a simple configuration.

[0053] Also, in relation to the above Modification 1 (FIG. 4(b)), a press-fitting portion 41e may be formed by a part of the main body portion 41c being plastically deformed and bulging radially outward during the process of fastening the mounting bolt 40 to the fastening hole 50. Specifically, before the mounting bolt 40 is fastened to the fastening hole 50, a part of the main body portion 41c of the collar 41 is formed to be thin (in other words, the dimension in the radial direction is small). When the mounting bolt 40 is fastened to the fastening hole 50, the main body portion 41c is sandwiched between the head portion 40a of the mounting bolt 40 and the bottom surface of the insertion hole 53, and the thin portion that is easily deformed in the main body portion 41c is plastically deformed so as to bulge radially outward, and the press-fitting portion 41e is formed.

[0054] <Modification 4> In the above-described embodiment, the discharge port 22a is provided at the tip surface of the protruding portion 22 of the cover portion 20. Instead of this, a configuration may be adopted in which a suction port 21a for guiding liquid to the pump portion is provided at the tip surface of the protruding portion 22 of the cover portion 20. In this case, the discharge port 22a is provided on the surface of the disk portion 21 of the cover portion 20. Thus, the protruding portion 22 of the cover portion 20 is provided with, as a port, the suction port 21a for guiding liquid to the pump portion or the discharge port 22a for guiding the liquid discharged from the pump portion. Further, the protruding portion 22 may not be formed on the cover portion 20, and the suction port 21a and the discharge port 22a may be formed on the surface of the disk portion 21 of the cover portion 20. In that case, the disk portion 21 of the cover portion 20 abuts against the bottom surface of the housing recess 51, and the suction port 21a and the discharge port 22a communicate with the openings formed in the bottom surface of the housing recess 51, respectively.

[0055] <Modification Example 5> In the above-described embodiment, the attached body 102 has a housing recess 51 that houses a part of the housing 2 of the electric pump 101, and an opening 52 that is formed in the bottom surface of the housing recess 51 and into which the protruding portion 22 of the housing 2 is inserted. However, the housing recess 51 is not an essential configuration of the present invention. In this case, as shown in FIG. 7, the housing recess 51 is not formed in the end surface 102a of the attached body 102, and the opening 52 is formed in the end surface 102a of the attached body 102. Further, the suction port 21a for guiding liquid to the pump portion communicates with a passage (not shown) formed in the end surface 102a of the attached body 102.

[0056] <Modification Example 6> In the above-described embodiment, the object to be attached to the attached body 102 has been described by taking the electric pump 101 as an example. However, the object to be attached to the attached body 102 is not limited to the electric pump 101, and it may be a simple pump. In that case, only the pump portion is housed in the housing 2, and the drive shaft is rotatably supported by the housing 2. That is, the motor portion and the controller are not housed in the housing 2.

[0057] Hereinafter, the configuration, operation, and effects of the embodiments of the present invention will be collectively described.

[0058] In an attachment structure 100 for attaching a housing 2 of a pump (electric pump 101) to an object to be attached 102 via a mounting bolt 40 as a fastening member, the housing 2 has a through hole 31 through which the mounting bolt 40 is inserted and a port that opens to the outer surface of the housing 2. The object to be attached 102 has a fastening hole 50 formed corresponding to the through hole 31 of the housing 2 and to which the mounting bolt 40 is fastened, and an opening 52 that communicates with the port of the housing 2. The port is a suction port 21a that guides liquid to the pump or a discharge port 22a that guides liquid discharged from the pump. The attachment structure 100 includes a collar 41 provided through the through hole 31 as a cylindrical member through which the mounting bolt 40 is inserted, and an insertion hole 53 provided coaxially with the fastening hole 50 and into which the tip portion 41b of the collar 41 is inserted. The collar 41 is provided across the through hole 31 of the housing 2 and the insertion hole 53 of the object to be attached 102, thereby positioning the housing 2 with respect to the object to be attached 102. The collar 41 has a large-diameter portion 41d formed at the base end portion and sandwiched between the head portion 40a of the mounting bolt 40 and the housing 2.

[0059] In this configuration, an insertion hole 53 in which a collar 41 for positioning the housing 2 with respect to the object to be attached 102 is provided is provided in a fastening hole 50 to which a mounting bolt 40 for attaching the housing 2 to the object to be attached 102 is fastened. Further, both the mounting bolt 40 and the collar 41 are provided in the through hole 31 of the housing 2. In this way, the mounting bolt 40 and the collar 41 having different functions are provided at a common position. Therefore, the mounting accuracy of the pump with respect to the object to be attached 102 can be improved at low cost.

[0060] Further, in the attachment structure 100, the collar 41 further has a press-fitting portion 41e formed such that at least a part thereof has a larger diameter than the inner diameters of the through hole 31 and the insertion hole 53.

[0061] In this configuration, by managing the position of the press-fitting portion 41e and press-fitting the collar 41 across the through hole 31 and the insertion hole 53, the positioning of the housing 2 with respect to the object to be attached 102 can be made accurate.

[0062] Further, in the mounting structure 100, the press-fitting portion 41e is formed in a tapered shape such that the outer diameter increases toward the base end portion of the collar 41.

[0063] In this configuration, in the process of press-fitting the collar 41 into the through hole 31 and the insertion hole 53, the through hole 31 and the insertion hole 53 can be easily arranged coaxially.

[0064] Further, in the mounting structure 100, the housing 2 further has a housing hole 30c formed in the through hole 31 and accommodating at least a part of the large-diameter portion 41d of the collar 41. The outer peripheral surface of the large-diameter portion 41d of the collar 41 contacts the inner peripheral surface of the housing hole 30c, and the outer peripheral surface of the tip portion 41b contacts the inner peripheral surface of the insertion hole 53, whereby the housing 2 is positioned with respect to the mounted body 102.

[0065] In this configuration, since high machining accuracy is not required for the inner peripheral surface of the through hole 31, the machining of the housing 2 becomes easy.

[0066] Further, in the mounting structure 100, the large-diameter portion 41d of the collar 41 is formed by being plastically deformed by the head portion 40a of the mounting bolt 40 in the process of fastening the mounting bolt 40 to the fastening hole 50.

[0067] In this configuration, the collar 41 can be made into a simple configuration.

[0068] As described above, the embodiments of the present invention have been described. However, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Explanation of Reference Numerals

[0069] 2 … Housing, 21a … Suction port, 22a … Discharge port, 30c … Accommodation hole, 31 … Through hole, 40 … Mounting bolt (fastening member), 40a … Head, 41 … Collar (cylindrical member), 41a … Hollow portion, 41b … Tip portion, 41d … Large diameter portion, 41e … Press-fitting portion, 50 … Fastening hole, 52 … Opening, 53 … Insertion hole, 100 … Mounting structure, 101 … Electric pump, 102 … Object to be mounted

Claims

1. An attachment structure for attaching a pump housing to an object to be attached via a fastening member, wherein the housing has a through-hole through which the fastening member is inserted, and a port that opens to the outer surface of the housing, and the object to be attached has a fastening hole formed corresponding to the through-hole of the housing and to which the fastening member is fastened, and an opening that communicates with the port of the housing, and the port is a suction port for guiding liquid to the pump or a discharge port for guiding liquid discharged from the pump, and the attachment structure has a cylindrical member provided through the through-hole and having a hollow portion through which the fastening member is inserted, and an insertion hole provided coaxially with the fastening hole and into which the tip of the cylindrical member is inserted, wherein the cylindrical member is provided across the through-hole of the housing and the insertion hole of the object to be attached, thereby positioning the housing with respect to the object to be attached, and the cylindrical member has a large-diameter portion formed at the base end portion and sandwiched between the head of the fastening member and the housing, characterized in that it is a pump attachment structure.

2. The pump attachment structure according to claim 1, wherein the cylindrical member further has a press-fitting portion at least a part of which is formed to have a diameter larger than the inner diameters of the through-hole and the insertion hole, characterized in that it is a pump attachment structure.

3. The pump attachment structure according to claim 2, wherein the press-fitting portion is formed in a tapered shape such that the outer diameter increases toward the base end portion of the cylindrical member, characterized in that it is a pump attachment structure.

4. The pump attachment structure according to claim 1, wherein the housing further has a housing hole formed in the through-hole and at least a part of the large-diameter portion of the cylindrical member is accommodated therein, and the outer peripheral surface of the large-diameter portion of the cylindrical member contacts the inner peripheral surface of the housing hole, and the outer peripheral surface of the tip portion contacts the inner peripheral surface of the insertion hole, whereby the housing is positioned with respect to the object to be attached, characterized in that it is a pump attachment structure.

5. The pump attachment structure according to claim 1, wherein the large-diameter portion of the cylindrical member is formed by being plastically deformed by the head of the fastening member in the process of fastening the fastening member to the fastening hole, characterized in that it is a pump attachment structure.

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