Oil pressure sensor attachment structure

1. An oil pressure sensor attachment structure in which an oil pressure sensor for measuring a pressure of an oil flowing in an oil path through which the oil flows is attached to an oil path body having the oil path therein,

wherein the oil path body has a lower body, and an upper body which is disposed to overlap the lower body in an up and down direction,

wherein the lower body has an oil path opening portion which is connected to the oil path on an upper surface of the lower body,

wherein the oil pressure sensor has a sensor main body, and a sensor case which covers the sensor main body, and

wherein the sensor case is installed on the upper surface of the lower body and has a sensing hole on the lower surface of the sensor case, which is connected to the oil path opening portion in a state where the sensor case is installed on the upper surface of the lower body,

wherein the oil pressure sensor attachment structure comprises:

the oil path body;

the sensor case; and

a seal member which seals a portion between the oil path body and the sensor case,

wherein the oil path body has an accommodation hole portion which accommodates the oil pressure sensor in a state where at least a portion of the oil pressure sensor is disposed between the upper body and the lower body in the up and down direction,

wherein the accommodation hole portion has

a small-diameter hole portion, and

a large-diameter hole portion which is disposed on the lower side of the small-diameter hole portion in the up and down direction and of which an inner diameter is larger than the small-diameter hole portion,

wherein the sensor case has

a columnar portion which is disposed along a central axis extending in the up and down direction and of which at least a portion is inserted into the small-diameter hole portion, and

a flange portion which protrudes from the columnar portion to an outside in a radial direction and is inserted into the large-diameter hole portion,

wherein the flange portion is disposed to face a lower side of the upper body in the up and down direction, and

wherein the seal member has an annular shape surrounding the columnar portion on an upper side of the flange portion in the up and down direction, and seals a portion between an inner surface of the accommodation hole portion and the sensor case.

2. The oil pressure sensor attachment structure according to claim 1 ,

wherein the outer diameter of the columnar portion is smaller than the inner diameter of the small-diameter hole portion, and

wherein the outer diameter of the flange portion is larger than the inner diameter of the small-diameter hole portion and is smaller than the inner diameter of the large-diameter hole portion.

3. The oil pressure sensor attachment structure according to claim 1 ,

wherein the accommodation hole portion has a medium-diameter hole portion which connects the small-diameter hole portion and the large-diameter hole portion to each other between the small-diameter hole portion and the large-diameter hole portion in the up and down direction,

wherein the inner diameter of the medium-diameter hole portion is larger than the inner diameter of the small-diameter hole portion and is smaller than the inner diameter of the large-diameter hole portion, and

wherein the seal member is fitted into the medium-diameter hole portion.

4. The oil pressure sensor attachment structure according to claim 3 ,

wherein the columnar portion passes through the medium-diameter hole portion,

wherein a first gap is provided between an inner circumferential surface of the medium-diameter hole portion and an outer circumferential surface of the columnar portion in the radial direction, and

wherein a dimension of the first gap in the radial direction is smaller than a dimension of the seal member in a state of not being deformed in the radial direction.

5. The oil pressure sensor attachment structure according to claim 3 ,

wherein the flange portion faces, a first stepped surface facing downward in the up and down direction, in the up and down direction in a first stepped portion between the medium-diameter hole portion and the large-diameter hole portion, and

wherein a dimension, between the first stepped surface and a second stepped surface facing downward in the up and down direction, in the up and down direction in a second stepped portion between the small-diameter hole portion and the medium-diameter hole portion is larger than a dimension of the seal member in the up and down direction.

6. The oil pressure sensor attachment structure according to claim 3 ,

wherein an end portion of a lower side of the medium-diameter hole portion in the up and down direction is an enlarged diameter portion of which an inner diameter becomes large from an upper side in the up and down direction to a lower side in the up and down direction.

7. The oil pressure sensor attachment structure according to claim 3 ,

wherein the accommodation hole portion is a hole which is recessed from a lower surface of the upper body to an upper side in the up and down direction.

8. The oil pressure sensor attachment structure according to claim 7 ,

wherein the columnar portion has a groove portion into which the seal member is fitted, on an outside in a radial direction.

9. The oil pressure sensor attachment structure according to claim 8 ,

wherein the seal member is an O-ring.