Pump mounting structure

Abstract

In a mounting structure (100) for mounting a housing (2) of a pump (electric pump (101)) to a mount (102) via a mounting bolt (40), the housing (2) has a through-hole (31) through which the mounting bolt (40) is inserted and a port opening onto the exterior surface of the housing (2). The mount (102) has a fastening hole (50) formed in correspondence with the through-hole (31) of the housing (2) and into which the mounting bolt (40) is fastened, and an opening (52) connected to the port of the housing (2). The mounting structure (100) comprises: a collar (41) provided inserted through the through-hole (31) and through a hollow portion (41a) of which the mounting bolt (40) is inserted; and an insertion hole (53) provided coaxially with the fastening hole (50) and into which a leading end portion (41b) of the collar (41) is inserted. The collar (41) has a large-diameter portion (41d) formed at a base end portion thereof and sandwiched between a head portion (40a) of the mounting bolt (40) and the housing (2).

Description

Pump mounting structure

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

[0002] JP2021-4604A discloses an electric pump device mounting structure including an electric pump device and a mounting surface to which the electric pump device is mounted. In this mounting structure, a positioning portion of the electric pump device fits into a positioning portion of the mounting surface of the mounting surface, thereby ensuring the mounting accuracy of the electric pump device to the mounting surface.

[0003] In JP2021-4604A, 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. This requires a dedicated hole portion into which the pin portion is press-fitted, which increases the manufacturing cost of the electric pump.

[0004] An object of the present invention is to improve the mounting accuracy of a pump to a mounting body at low cost.

[0005] According to one aspect of the present invention, there is provided an attachment structure for attaching a pump housing to a workpiece via a fastening member, the housing having a through hole through which the fastening member is inserted and a port opening on the outer surface of the housing, the workpiece having a fastening hole formed corresponding to the through hole of the housing and through which the fastening member is fastened and an opening through which the port of the housing communicates, the port being an intake port for guiding liquid to the pump or an outlet port for guiding liquid discharged from the pump, the attachment structure comprising: a cylindrical member inserted through the through hole and having a hollow portion through which the fastening member is inserted; and an insertion hole formed coaxially with the fastening hole and into which the tip of the cylindrical member is inserted, the cylindrical member being positioned across the through hole of the housing and the insertion hole of the workpiece, thereby positioning the housing relative to the workpiece, the cylindrical member having a large diameter portion formed at a base end and sandwiched between the head of the fastening member and the housing.

[0006] FIG. 1 is a side view of an electric pump and a mounting body according to an embodiment of the present invention, with the mounting body shown in cross section. FIG. 2 is a perspective view of the electric pump according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of a mounting structure according to an embodiment of the present invention. FIG. 4 is a cross-sectional view of a collar according to a first modified embodiment of the present invention. FIG. 5 is a cross-sectional view of a mounting structure according to a second modified embodiment of the present invention. FIG. 6 is a cross-sectional view of a mounting structure according to a third modified embodiment of the present invention. FIG. 7 is a side view of an electric pump and a mounting body according to a fifth modified embodiment of the present invention, with the mounting body shown in cross section. FIG. 8 is a cross-sectional view of a mounting structure according to a comparative example of an embodiment of the present invention.

[0007] Hereinafter, a mounting structure 100 according to an embodiment of the present invention will be described with reference to the drawings. The mounting structure 100 is for mounting an electric pump 101 to a mounting target 102 via mounting bolts 40 as fastening members.

[0008] 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 oil (liquid) for lubricating gears mounted on the vehicle. The electric pump 101 may also be used as a fluid pressure supply source that discharges a working fluid (liquid) for driving equipment. The electric pump 101 may also be mounted on industrial machinery other than a vehicle.

[0009] First, the electric pump 101 and the mounting body 102 will be described with reference to Figures 1 and 2. Figure 1 is a side view of the electric pump 101 mounted on the mounting body 102, with the mounting body 102 shown in cross section. Figure 2 is a perspective view of the electric pump 101 alone.

[0010] As shown in FIGS. 1 and 2 , the electric pump 101 has a housing 2 that houses a pump unit and a motor unit that are connected via a drive shaft (not shown). The housing 2 also houses a controller that controls the operation of the motor unit. In this manner, the electric pump 101 is a unit in which the pump unit, motor unit, and controller are housed within the housing 2. The drive shaft is rotatably supported by the housing 2 via a bearing. In this embodiment, the pump unit is an internal gear pump that has an inner rotor connected to the drive shaft and an outer rotor disposed outside the inner rotor. The configuration of an internal gear pump is similar to that of a well-known configuration, so a detailed description will be omitted. Note that the pump unit is not limited to an internal gear pump and may be other pumps such as other gear pumps or vane pumps.

[0011] The housing 2 has a main body 10 and a cover 20 that is fixed to the main body 10 via fixing bolts 3 and seals an opening of the main body 10. In the following, the axial direction of the drive shaft will also be simply referred to as the "axial direction."

[0012] The main body 10 has a rectangular section 11 with a rectangular outer periphery and a circular section 12 with a circular outer periphery that is formed integrally with the rectangular section 11. A pump section is housed in a first circular section 12a on the distal end side of the circular section 12, and a motor section is housed in a second circular section 12b on the proximal end side of the circular section 12. A controller is housed within the rectangular section 11. The cover section 20 has a disk section 21 that has the same outer diameter as the circular section 12 and is attached to the end face of the circular section 12, and a protrusion 22 that protrudes from the disk section 21. The protrusion 22 protrudes parallel to the axial direction of the drive shaft, and the central axis of the protrusion 22 is offset from the central axis of the drive shaft.

[0013] An intake port 21a (see FIG. 1) for introducing liquid into the pump section is provided on the surface of the disk section 21. An outlet port 22a (see FIG. 1) for introducing liquid discharged from the pump section to the outside is provided on the tip surface of the protrusion 22. The intake port 21a and the outlet port 22a open to the outer surface of the housing 2. In FIG. 1, the intake port 21a and the outlet port 22a are indicated by dotted lines.

[0014] In the main body 10, the dimension of the rectangular portion 11 in a direction perpendicular to the drive shaft is larger than the outer diameter of the circular portion 12. Therefore, the rectangular portion 11 has an end face 11a that extends radially from the outer circumferential surface of the circular portion 12. The end face 11a abuts against an end face 102a of the mounting body 102, thereby determining the axial position of the electric pump 101 relative to the mounting body 102.

[0015] A plurality of flanges 30 are formed on the outer peripheral surface of the rectangular portion 11. End faces 30a of the flanges 30 and end faces 11a of the rectangular portion 11 are formed as a continuous surface. The flanges 30 are formed with through holes 31 through which mounting bolts 40 for fixing the electric pump 101 to the mounting body 102 are inserted.

[0016] The mounting body 102 is a case of a device that uses the liquid discharged from the electric pump 101. The device is, for example, a transmission or a transaxle device.

[0017] As shown in Figure 1, the mounting body 102 is formed to correspond to the through hole 31 of the housing 2 of the electric pump 101, and has a fastening hole 50 (see Figure 3) into which the mounting bolt 40 is fastened, an accommodating recess 51 that accommodates a portion of the housing 2, and an opening 52 formed in the bottom surface of the accommodating recess 51 and into which the protrusion 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 accommodating recess 51 are formed so as to open into the end surface 102a of the mounting body 102. The inner peripheral surface of the fastening hole 50 is formed with a female thread into which the male thread of the mounting bolt 40 is threaded.

[0018] When attaching the electric pump 101 to the attachment target 102, the circular portion 12 of the housing 2 of the electric pump 101 is accommodated in the accommodation recess 51 of the attachment target 102, and the end face 11a of the rectangular portion 11 of the housing 2 is abutted against the end face 102a of the attachment target 102 while the protrusion 22 of the housing 2 is inserted into the opening 52 of the attachment target 102. Then, the attachment bolt 40 is inserted into the through hole 31 of the housing 2 and fastened to the fastening hole 50 of the attachment target 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 attachment target 102, and attaching the electric pump 101 to the attachment target 102. When the electric pump 101 is attached to the attachment base 102, the space between the housing 2 and the bottom surface of the accommodation recess 51 of the attachment base 102, specifically the space between the cover portion 20 and the bottom surface of the accommodation recess 51, becomes a storage portion 4 in which liquid is stored. An intake port 21a provided on the surface of the disk portion 21 of the cover portion 20 faces the storage portion 4. Furthermore, when the electric pump 101 is attached to the attachment base 102, an outlet port 22a formed on the tip surface of the protrusion 22 communicates with the opening 52.

[0019] When the electric pump 101 is attached to the object to be attached 102 and the motor section of the electric pump 101 is driven, the pump section of the electric pump 101 draws liquid from the storage section 4 through the suction port 21a, discharges the pressurized liquid, and directs it to the opening 52 of the object to be attached 102 through the discharge port 22a.

[0020] A small gap exists between the outer peripheral surface of the circular portion 12 of the housing 2 and the inner peripheral surface of the accommodating recess 51. There is also a small 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 is provided on the outer peripheral surface of the protruding portion 22 as a sealing member. 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, sealing the gap between the two. Therefore, liquid guided to the opening 52 through the discharge port 22a of the protruding portion 22 is prevented from leaking into the accommodating recess 51 through the gap between the protruding portion 22 and the opening 52, and is supplied to the equipment through the opening 52. In other words, the O-ring 5 prevents communication between the discharge side and the suction side of the pump unit, thereby preventing a decrease in the performance of the pump unit. An O-ring (not shown) is also provided between the end face 11a of the rectangular portion 11 of the housing 2 and the end face 102a of the mounting body 102 as a sealing member to seal the gap between the two.

[0021] Here, when the electric pump 101 is fixed to the mounting body 102 using only the mounting bolts 40, gaps exist between the outer peripheral surface of the circular portion 12 of the housing 2 and the inner peripheral surface of the accommodating 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, so there is a risk that the central axis of the protruding portion 22 may be misaligned with the central axis of the opening 52 when inserted into the opening 52. In this 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.

[0022] Therefore, in this embodiment, in order to improve the mounting accuracy of the electric pump 101 to the mounting base 102, specifically, to improve the positioning accuracy of the protrusion 22 with respect to the opening 52, the mounting structure 100 has the following configuration. Figure 3 is a cross-sectional view of the mounting structure 100, where (a) shows a state in which the mounting bolt 40 is not fastened to the fastening hole 50, and (b) shows a state in which the mounting bolt 40 is fastened to the fastening hole 50.

[0023] As shown in Figure 3, the mounting structure 100 includes a collar 41 as a cylindrical member that is inserted through the through hole 31 and has a hollow portion 41a through which the mounting bolt 40 is inserted, and an insertion hole 53 that is arranged coaxially with the fastening hole 50 and into which the tip portion 41b of the collar 41 is inserted.

[0024] The insertion hole 53 is provided so as to open to the 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 approximately the same as the inner diameter of the through hole 31.

[0025] In this embodiment, the collar 41 is made of metal, but 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, across the housing 2 of the electric pump 101 and the mounting body 102) and serves to position the housing 2 relative to the mounting body 102. The collar 41 has a cylindrical main body portion 41c and a large diameter portion 41d formed at the base end. The main body portion 41c of the collar 41 is inserted into the through hole 31 and the insertion hole 53, and the large diameter portion 41d is provided in contact with the surface 30b of the flange 30.

[0026] The main body 41c has an outer diameter substantially equal to the inner diameters of the through hole 31 and the insertion hole 53, and an inner diameter larger than the outer diameter of the mounting bolt 40. The axial length of the main body 41c is longer than the axial length of the through hole 31 and smaller than the sum of the axial lengths of the through hole 31 and the insertion hole 53. Therefore, the tip 41b of the collar 41 is positioned within the insertion hole 53 and does not contact the bottom surface of the insertion hole 53. When the collar 41 is inserted into the through hole 31 and the insertion hole 53, the outer peripheral surface of the main body 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 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 mounting body 102 in this manner, the housing 2 is positioned relative to the mounting body 102.

[0027] The large diameter portion 41d is formed to have a diameter larger than the head 40a of the mounting bolt 40. When the mounting bolt 40 is fastened into the fastening hole 50, as shown in FIG. 3B, 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 bearing surface for the mounting bolt 40. Therefore, the large diameter portion 41d can ensure the area of ​​the bearing surface for the mounting bolt 40.

[0028] To attach the electric pump 101 to the workpiece 102, the circular portion 12 of the housing 2 is accommodated in the receiving recess 51 of the workpiece 102, the protruding portion 22 of the housing 2 is inserted into the opening 52 of the workpiece 102, and the through-hole 31 and the insertion hole 53 are aligned. The collar 41 is then inserted into the through-hole 31 and the insertion hole 53. Attaching the electric pump 101 to the workpiece 102 via the collar 41 improves the attachment accuracy of the electric pump 101 to the workpiece 102, thereby improving the positioning accuracy of the protruding portion 22 relative to the opening 52. This aligns the central axis of the protruding portion 22 with the central axis of the opening 52, making the compression amount of the O-ring 5 uniform in the circumferential direction and improving the sealing performance of the O-ring 5. After attaching the electric pump 101 to the workpiece 102 via the collar 41, the electric pump 101 is fixed to the workpiece 102 using the mounting bolts 40.

[0029] In this way, in the mounting structure 100, the insertion hole 53 in which the collar 41 for positioning the housing 2 relative to the mounting base 102 is provided is provided in the fastening hole 50 in which the mounting bolt 40 for mounting the housing 2 to the mounting base 102 is fastened. Furthermore, both the mounting bolt 40 and the collar 41 are provided in the through hole 31 of the housing 2. In this way, in the mounting structure 100, the mounting bolt 40 and the collar 41, which have different functions, are provided in the same position. Therefore, compared to when the mounting bolt 40 and the collar 41 are provided in different positions, the mounting accuracy of the electric pump 101 relative to the mounting base 102 can be improved at low cost.

[0030] Furthermore, in the mounting structure 100, the insertion holes 53 are formed coaxially with the fastening holes 50. Therefore, the processing of the insertion holes 53 can be performed simultaneously with the processing of the fastening holes 50. In other words, the processing of the insertion holes 53 and the fastening holes 50, which have different functions, can be performed simultaneously. Therefore, compared to the case where the insertion holes 53 and the fastening holes 50 are separately processed in different locations, the number of processing steps can be reduced and processing accuracy can be improved.

[0031] 8 shows a mounting structure 200, as a comparative example of this embodiment, in which a cylindrical collar 141 without a 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, instead of the through hole 31, the flange 30 is formed with a bolt hole 131 that opens to the front surface 30b and through which the mounting bolt 40 is inserted, and a collar hole 132 that opens to the end face 30a and is provided coaxially with the bolt hole 131. The inner diameter of the collar hole 132 is formed to be larger than the inner diameter of the bolt hole 131 and to be approximately the same as the inner diameter of the insertion hole 53. In this way, the collar 141 is provided in the collar hole 132, which is not a through hole.

[0032] In the mounting structure 200, to mount the electric pump 101 to the mounting base 102, the collar 141 is first press-fitted and fixed into the collar hole 132. Then, while the circular portion 12 of the housing 2 is accommodated in the accommodating recess 51 of the mounting base 102, the protruding portion 22 of the housing 2 is inserted into the opening 52 of the mounting base 102, and the collar 141 is press-fitted into the insertion hole 53 of the mounting base 102. At this time, the collar 141 press-fitted into the collar hole 132 of the flange 30 must be press-fit perpendicularly to the end face 102a, which makes mounting the electric pump 101 time-consuming. In contrast, in the mounting structure 100 of this embodiment, it is not necessary to previously install the collar 41 in the through hole 31 or the insertion hole 53 during mounting. After inserting the protruding portion 22 of the housing 2 into the opening 52 of the mounting base 102, the collar 41 can be easily mounted through the through hole 31. Therefore, assembly is easier than with the mounting structure 200.

[0033] Furthermore, in the mounting structure 100 and the comparative example 200, the projection allowance of the collars 41, 141 (in other words, the length by which the collars 41, 141 protrude into the insertion hole 53) must be controlled so that the collars 41, 141 do not contact the bottom surface of the insertion hole 53. In the mounting structure 200 of the comparative example, the collar 141 is press-fit into the collar hole 132, resulting in a slight gap between the collar 141 and the bottom surface of the collar hole 132. The amount of this gap affects the projection allowance of the collar 141, making it difficult to control the projection allowance of the collar 141. In contrast, in the mounting structure 100 of this embodiment, the large-diameter portion 41d formed at the base end of the collar 41 is fixed by the mounting bolt 40. Therefore, the projection allowance 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. This makes it easy to control the projection allowance of the collar 41.

[0034] In this embodiment, as shown in Fig. 2, a plurality of through holes 31 are formed. It is preferable that the collar 41 be provided in all of the plurality of through holes 31, but the collar 41 may be provided only in a specific through hole 31. The configuration is not limited to a 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 attachment target body 102 with only one attachment bolt 40. Even with these configurations, the attachment accuracy of the electric pump 101 to the attachment target body 102 is improved.

[0035] According to the above embodiment, the following advantageous effects are achieved.

[0036] In the mounting structure 100, an insertion hole 53 in which a collar 41 for positioning the housing 2 relative to the mounting base 102 is provided is provided in a fastening hole 50 in which a mounting bolt 40 for mounting the housing 2 to the mounting base 102 is fastened. Furthermore, 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, which have different functions, are provided in a common position. Therefore, compared to when the mounting bolt 40 and the collar 41 are provided in different positions, the mounting accuracy of the electric pump 101 relative to the mounting base 102 can be improved at low cost.

[0037] Next, modifications of the above embodiment will be described. The following modifications are also within the scope of the present invention, and it is possible to combine the following modifications with the configuration of the above embodiment, or to combine the following modifications with each other.

[0038] <Modification 1> In the above embodiment, the collar 41 is provided such that the outer diameter of the main body portion 41c is substantially the same as the inner diameters of the through hole 31 and the insertion hole 53, and the outer peripheral surfaces of the main body portion 41c are fitted into the inner peripheral surfaces of the through hole 31 and the insertion hole 53. However, if high precision is required for mounting the electric pump 101, the collar 41 may be provided by being press-fitted into the through hole 31 and the insertion hole 53. In other words, as shown in FIG. 4 , the collar 41 has a press-fit portion 41e, at least a portion of which is formed with a diameter larger than the inner diameters of the through hole 31 and the insertion hole 53.

[0039] Specifically, as shown in FIG. 4( a), the press-fit portion 41e is formed in a tapered shape with an outer diameter increasing toward the base end (large-diameter portion 41d) of the collar 41. Alternatively, as shown in FIG. 4( b), the press-fit portion 41e is formed by protruding radially outward from a portion of the main body portion 41c over the entire circumference. Alternatively, the entire main body portion 41c may be 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-fit portion 41e), in which case the press-fit portion 41e may be knurled. In these configurations, the collar 41 can be press-fit into the through hole 31 and the insertion hole 53 by fastening the mounting bolt 40 into the fastening hole 50 with a portion of the collar 41 inserted in the through hole 31 (specifically, with the collar 41 not press-fitted into the through hole 31 and the press-fit portion 41e exposed from the through hole 31). Furthermore, by controlling the position of the press-fit portion 41e and providing the press-fit portion 41e 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, it is possible to accurately position the housing 2 relative to the attached body 102. Furthermore, if the press-fit portion 41e is formed in a tapered shape as shown in Figure 4(a), 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 are guided by the press-fit portion 41e and aligned so as to be positioned coaxially, so that the through hole 31 and the insertion hole 53 can be easily positioned coaxially.

[0040] <Modification 2> In the above embodiment, the collar 41 is provided with the large diameter portion 41d in contact with the surface 30b of the flange 30. However, this is not limited to this. As shown in FIG. 5 , the housing 2 may have an accommodating hole 30c, at least a portion of the large diameter portion 41d of the collar 41 is accommodated in the accommodating 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 accommodating hole 30c. The accommodating hole 30c is formed in the through hole 31. Specifically, the accommodating hole 30c is formed coaxially with the through hole 31 in the surface 30b of the flange 30, and the inner peripheral surface of the accommodating hole 30c is in radial contact with the outer peripheral surface of the large diameter portion 41d over the entire circumference. Furthermore, the outer peripheral surface of the tip end 41b of the collar 41 contacts the inner peripheral surface of the insertion hole 53. The outer peripheral surface of the large diameter portion 41d contacts the inner peripheral surface of the accommodation hole 30c, and the outer peripheral surface of the tip portion 41b contacts the inner peripheral surface of the insertion hole 53, thereby positioning the housing 2 with respect to the mounting base 102. In this configuration, the inner peripheral surface of the through hole 31 is not used for positioning, so high machining accuracy for positioning is not required. This makes machining of the housing 2 easier.

[0041] <Modification 3> In the above embodiment, the collar 41 already has a large diameter portion 41d formed at the base end. 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 plastic deformation by the head 40a of the mounting bolt 40 during the process of fastening the mounting bolt 40 to the fastening hole 50. In FIG. 6 (a), the mounting bolt 40 is not fastened to the fastening hole 50, and FIG. 6 (b) shows the mounting bolt 40 fastened to the fastening hole 50. In this case, the collar 41 may be formed of a material that easily undergoes plastic deformation, 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 Figure 6(b), when the mounting bolt 40 is fastened into the fastening hole 50, the base end (left side in Figure 6) of the collar 41 is gradually crushed and deformed by the head 40a, expanding radially outward to form a large diameter portion 41d. The base end of the collar 41 may be tapered to facilitate plastic deformation radially outward. This configuration allows the collar 41 to have a simple configuration.

[0042] Furthermore, in relation to the above-described modified example 1 ( FIG. 4( b) ), a portion of the main body portion 41 c may be plastically deformed and bulge radially outward during the process of fastening the mounting bolt 40 into the fastening hole 50, thereby forming the press-fit portion 41 e. Specifically, before the mounting bolt 40 is fastened into the fastening hole 50, a portion of the main body portion 41 c of the collar 41 is formed to be thin-walled (in other words, with a small radial dimension). When the mounting bolt 40 is fastened into the fastening hole 50, the main body portion 41 c is sandwiched between the head 40 a of the mounting bolt 40 and the bottom surface of the insertion hole 53, and the thin-walled portion of the main body portion 41 c, which is easily deformed, is plastically deformed so as to bulge radially outward, thereby forming the press-fit portion 41 e.

[0043] <Modification 4> In the above embodiment, the discharge port 22a is provided on the tip surface of the protruding portion 22 of the cover portion 20. Alternatively, the tip surface of the protruding portion 22 of the cover portion 20 may be provided with a suction port 21a for guiding liquid to the pump portion. In this case, the discharge port 22a is provided on the surface of the circular plate portion 21 of the cover portion 20. In this manner, 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 liquid discharged from the pump portion. Furthermore, the protruding portion 22 does not have to 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 circular plate portion 21 of the cover portion 20. In this case, the circular plate portion 21 of the cover portion 20 abuts against the bottom surface of the accommodating recess 51, and the suction port 21a and the discharge port 22a are respectively connected to openings formed in the bottom surface of the accommodating recess 51.

[0044] <Variation 5> In the above embodiment, the mounting base 102 has an accommodating recess 51 that accommodates a portion of the housing 2 of the electric pump 101, and an opening 52 formed on the bottom surface of the accommodating recess 51 and into which the protrusion 22 of the housing 2 is inserted. However, the accommodating recess 51 is not an essential component of the present invention. In this case, as shown in Figure 7, the accommodating recess 51 is not formed in the end surface 102a of the mounting base 102, and the opening 52 is formed in the end surface 102a of the mounting base 102. In addition, the suction port 21a that introduces liquid to the pump section communicates with a passage (not shown) formed in the end surface 102a of the mounting base 102.

[0045] <Variation 6> In the above embodiment, the electric pump 101 has been described as an example of the object to be attached to the attachment base 102. However, the object to be attached to the attachment base 102 is not limited to the electric pump 101, and may simply be a pump. In this case, only the pump unit is housed within the housing 2, and the drive shaft is rotatably supported by the housing 2. In other words, the motor unit and the controller are not housed within the housing 2.

[0046] The configuration, operation, and effects of the embodiment of the present invention will be described below.

[0047] In a mounting structure 100 for mounting a housing 2 of a pump (electric pump 101) to a mounting target 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 on the outer surface of the housing 2, and the mounting target 102 has a fastening hole 50 formed corresponding to the through hole 31 of the housing 2 and into which the mounting bolt 40 is fastened and an opening 52 that communicates with the port of the housing 2, and the port is an inlet 21a that introduces liquid to the pump or an outlet 22 that introduces liquid discharged from the pump. a, and the mounting structure 100 comprises a collar 41 as a cylindrical member that is inserted through the through hole 31 and has a hollow portion 41a through which the mounting bolt 40 is inserted, and an insertion hole 53 that is provided coaxially with the fastening hole 50 and into which a tip portion 41b of the collar 41 is inserted, the collar 41 being provided across the through hole 31 of the housing 2 and the insertion hole 53 of the body 102 to be mounted, thereby positioning the housing 2 relative to the body 102 to be mounted, and the collar 41 has a large diameter portion 41d formed at its base end that is clamped between the head 40a of the mounting bolt 40 and the housing 2.

[0048] In this configuration, the insertion hole 53, in which the collar 41 for positioning the housing 2 relative to the mounting base 102 is provided, is provided in the fastening hole 50, into which the mounting bolt 40 for mounting the housing 2 to the mounting base 102 is fastened. Furthermore, 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, which have different functions, are provided in a common position. This allows the mounting accuracy of the pump relative to the mounting base 102 to be improved at low cost.

[0049] In addition, in the mounting structure 100 , the collar 41 further has a press-fit portion 41 e , at least a portion of which is formed with a diameter larger than the inner diameter of the through hole 31 and the insertion hole 53 .

[0050] In this configuration, by controlling the position of the press-fit portion 41 e and press-fitting the collar 41 through the through hole 31 and the insertion hole 53 , the housing 2 can be accurately positioned relative to the mounting body 102 .

[0051] In addition, in the mounting structure 100, the press-fit portion 41e is formed in a tapered shape such that the outer diameter increases toward the base end of the collar 41.

[0052] 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 aligned coaxially.

[0053] In addition, in the mounting structure 100, the housing 2 further has an accommodating hole 30c formed in the through hole 31 and accommodating at least a portion of the large diameter portion 41d of the collar 41, and the outer surface of the large diameter portion 41d of the collar 41 contacts the inner surface of the accommodating hole 30c, and the outer surface of the tip portion 41b contacts the inner surface of the insertion hole 53, thereby positioning the housing 2 relative to the body to be mounted 102.

[0054] In this configuration, the inner peripheral surface of the through hole 31 does not require high machining accuracy, and therefore machining of the housing 2 becomes easy.

[0055] Furthermore, in the mounting structure 100 , the large diameter portion 41 d of the collar 41 is formed by being plastically deformed by the head 40 a of the mounting bolt 40 during the process of fastening the mounting bolt 40 into the fastening hole 50 .

[0056] In this configuration, the collar 41 can be made to have a simple configuration.

[0057] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0058] This application claims priority based on Japanese Patent Application No. 2023-203781, filed with the Japan Patent Office on December 1, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A mounting structure for mounting a pump housing to a substrate via a fastening member, wherein the housing has a through hole through which the fastening member is inserted and a port opening on an outer surface of the housing, the substrate has a fastening hole formed corresponding to the through hole of the housing and through which the fastening member is fastened, and an opening through which the port of the housing communicates, the port being an intake port for directing liquid to the pump or an exhaust port for directing liquid discharged from the pump, the mounting structure comprising: a cylindrical member provided through the through hole and through which the fastening member is inserted, and an insertion hole provided coaxially with the fastening hole and through which a tip end of the cylindrical member is inserted, the cylindrical member being provided across the through hole of the housing and the insertion hole of the substrate to position the housing with respect to the substrate, and the cylindrical member having a large diameter portion formed at a base end and sandwiched between a head of the fastening member and the housing.

2. A pump mounting structure as claimed in claim 1, wherein the cylindrical member further has a press-fit portion, at least a part of which is formed with a diameter larger than the inner diameter of the through hole and the insertion hole.

3. A pump mounting structure as claimed in claim 2, wherein the press-fit portion is formed in a tapered shape with an outer diameter increasing toward the base end of the cylindrical member.

4. A pump mounting structure as described in claim 1, wherein the housing further has an accommodation hole formed in the through hole into which at least a portion of the large diameter portion of the cylindrical member is accommodated, and the outer circumferential surface of the large diameter portion of the cylindrical member contacts the inner circumferential surface of the accommodation hole and the outer circumferential surface of the tip end contacts the inner circumferential surface of the insertion hole, thereby positioning the housing relative to the object to be mounted.

5. A pump mounting structure as described in claim 1, wherein the large diameter portion of the cylindrical member is formed by plastic deformation by the head of the fastening member in the process of fastening the fastening member into the fastening hole.

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