JP2017096190A - Drain structure of oil pan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a drain plug from unexpectedly coming into a non-closed state, and to allow the drain plug to be surely in the non-closed state when it is necessary to be in the non-closed state.SOLUTION: A drain plug 20 includes: a columnar closing part 21; a seal material 23; and a tool engaging/disengaging part 22 provided so as to face the outside of an oil pan. The drain plug rotates around a center line of a drain hole 10 and can be switched between a closed state and a non-closed state. Around a drain hole 10 outside of the oil pan 1, a wall part 13 is provided which extends so as to surround the tool engaging/disengaging part 22 and which protects the tool engaging/disengaging part 22.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a drain structure of an oil pan in which a drain hole is closed by, for example, a resin drain plug provided at the bottom of the oil pan.

  For example, an oil pan for storing oil is provided in a lower part of an engine of an automobile. In recent years, an oil pan has been made of a resin in order to reduce the weight of a vehicle. When the oil pan is made of resin, it has been proposed that the plug for closing the drain hole provided at the bottom of the oil pan is also made of resin (for example, see Patent Document 1).

  In Patent Document 1, a drain hole is formed at the bottom of the oil pan, and an outer annular wall portion surrounding the drain hole is provided so as to protrude to the outside of the oil pan. On the outer surface of the outer annular wall portion, a protrusion is formed that becomes higher toward the one side in the circumferential direction. In addition, an inner annular wall that protrudes into the oil pan is provided around the drain hole of the oil pan, and a claw that protrudes radially inward is formed at the end of the inner annular wall. Has been.

  On the other hand, the drain plug includes a columnar portion that is inserted into the drain hole. A spiral groove is formed on the outer peripheral surface of the columnar portion so that the claws are screwed together. Further, a flexible piece is formed at a portion of the columnar portion facing the outside of the oil pan so as to cover a part of the outer annular wall portion. Then, when the columnar part of the drain plug is inserted into the drain hole and rotated, the pawl is screwed into the spiral groove of the drain plug and the drain plug is screwed in, and the drain plug is allowed to be fully screwed. The flexure is engaged with the protrusion of the outer annular wall portion of the oil pan so that the looseness of the drain plug is suppressed.

US Pat. No. 8,701,916

  By the way, since the oil pan is located at the lower part of the vehicle, it is conceivable that an obstacle such as a stepping stone hits from the front during driving, for example, a curb hits. In Patent Document 1, as a drain plug loosening prevention structure, a flexible piece is provided in a portion of the drain plug facing the outside of the oil pan, and this flexible piece is engaged with a protrusion of the outer annular wall portion of the oil pan. Therefore, it is easy for an obstacle or the like to hit the flexible piece. Since the flexible piece is made of resin, it can be easily damaged when hit by an obstacle, and when the flexible piece hits, the drain plug loosens and becomes non-blocked, leading to oil leakage.

  Also, when changing the oil, it is necessary to loosen the drain plug from the outside using a tool or the like to make it non-occluded. However, if the drain plug is damaged by an obstacle, the tool or the like may be engaged with the drain plug. There is a fear that it cannot be done.

  The present invention has been made in view of such a point, and an object of the present invention is to prevent the drain plug from unexpectedly becoming unblocked when the drain plug is made of resin. In addition, when it is necessary to be in the non-blocking state, the non-blocking state can be surely achieved.

  In order to achieve the above object, in the present invention, the portion of the drain plug that faces the outside of the oil pan is protected.

The first invention is
In the drain structure of the oil pan (1) in which the drain hole (10) formed in the bottom of the resin oil pan (1) is closed by the resin drain plug (20),
The drain plug (20) is inserted into the drain hole (10) to close the drain hole (10), a columnar blocking part (21), the blocking part (21), and the drain hole (10) A tool engagement / disengagement unit provided to face the outside of the oil pan (1) and a tool for rotating the drain plug (20). (22) and rotating around the center line of the drain hole (10) to switch between a closed state and a non-closed state,
Around the drain hole (10) outside the oil pan (1), the drain plug (20) engages with the tool engagement / disengagement part (22) when the drain plug (20) is in the closed state. Rotation restraining portions (2a, 20e) for restraining the rotation of (20) and a protective wall portion (13) extending so as to surround the tool engaging / disengaging portion (22) and protecting the tool engaging / disengaging portion (22). ) And is provided.

  According to this configuration, the tool engagement / disengagement part of the drain plug is provided so as to face the outside of the oil pan. Therefore, the drain plug can be rotated by easily engaging the tool with the tool engagement / disengagement part. It becomes possible. When the drain plug is closed, the tool engagement / disengagement portion of the drain plug engages with the rotation suppression portion of the oil pan, so that the rotation of the drain plug is suppressed. At this time, since the tool engaging / disengaging portion is protected by the protective wall portion, for example, an obstacle or the like is less likely to hit the tool engaging / disengaging portion, and damage to the tool engaging / disengaging portion is prevented. Therefore, the state in which the drain plug is engaged with the rotation suppressing portion is maintained, and the drain plug can be prevented from being in a non-closed state.

  On the other hand, when switching the drain plug from the closed state to the non-closed state, the tool engagement / disengagement part is protected as described above, so that the tool is securely engaged with the tool engagement / disengagement part and switched to the non-closed state. It becomes possible.

The second invention is
In the drain structure of the oil pan (1) in which the drain hole (10) formed in the bottom of the resin oil pan (1) is closed by the resin drain plug (20),
The drain plug (20) is inserted into the drain hole (10) so as to close the drain hole (10), a columnar blocking part (21), A tool engagement / disengagement unit provided to face the outside of the oil pan (1) and a tool for rotating the drain plug (20). (22) and rotating around the center line of the drain hole (10) to switch between a closed state and a non-closed state,
Around the drain hole (10) in the oil pan (1), when the drain plug (20) is in the closed state, the drain plug (20) is engaged with the closed portion (21). ) Is provided with a rotation suppressing portion (11c) for suppressing the rotation of
A protective wall (13) that extends around the drain hole (10) outside the oil pan (1) so as to surround the tool engagement / disengagement portion (21) and protects the tool engagement / disengagement portion (21). ) Is provided.

  According to this configuration, the tool engagement / disengagement part of the drain plug is provided so as to face the outside of the oil pan. Therefore, the drain plug can be rotated by easily engaging the tool with the tool engagement / disengagement part. It becomes possible. When the drain plug is closed, the closed portion of the drain plug is engaged with the rotation suppressing portion of the oil pan, and thus the rotation of the drain plug is suppressed. At this time, since the closed portion of the drain plug is a portion to be inserted into the drain hole, an obstacle or the like does not hit, so that the closed portion is prevented from being damaged and the drain plug is engaged with the rotation suppressing portion. The combined state is maintained, and it is possible to prevent the drain plug from becoming an unblocked state.

  Further, since the tool engagement / disengagement part is protected by the protective wall part, for example, an obstacle or the like is less likely to hit the tool engagement / disengagement part, and damage to the tool engagement / disengagement part is prevented. Therefore, when the drain plug is switched from the closed state to the non-closed state, the tool can be reliably engaged with the tool engagement / disengagement unit and switched to the non-closed state.

3rd invention is 1st or 2nd invention,
Around the drain hole (10) of the oil pan (1), an annular wall portion (11) extending so as to surround the closing portion (21) of the drain plug (20) is provided in the oil pan (1). Provided to protrude inside,
In the vicinity of the base end of the annular wall (11), an oil drain hole (5a) that opens upstream from the sealing material (23) is formed.

  According to this configuration, when the drain plug is in the closed state, the annular wall portion of the oil pan surrounds the closed portion of the drain plug, so that the drain plug is stabilized in the closed state. At this time, since the oil drain hole is closed, there is no oil leakage from the oil drain hole. On the other hand, when draining the oil, if the drain plug is not closed, the oil draining hole is opened and the oil is also drained from the vicinity of the base end of the annular wall. Therefore, it is possible to prevent oil from remaining in the oil pan.

According to a fourth invention, in the first invention,
A flange (24) is formed on the tool engagement / disengagement part (22) of the drain plug (20),
At least one of the outer surface (2) of the oil pan (1) and the surface (24a) of the flange (24) facing the outer surface (2) of the oil pan (1) is provided with the rotation suppressing portion ( 2a, 20e), and the other is provided with an engaging portion (24b) that engages with the rotation suppressing portion (2a, 20e).

  According to this configuration, since the engaging portion is provided on the surface of the drain plug flange facing the oil pan, the engaging portion does not hit the obstacle, and the engaging portion is prevented from being damaged. Therefore, the engaging portion can be reliably engaged with the rotation suppressing portion.

  According to the first invention, around the drain hole outside the oil pan, a rotation suppressing portion that engages with the tool engagement / disengagement portion of the drain plug in a closed state to suppress the rotation of the drain plug; Since the protective wall part that protects the tool engagement / disengagement part is provided, it is possible to prevent the drain plug from unintentionally becoming unoccluded, and when it is necessary to make it unoccluded, the tool can be removed. It can be used easily and reliably in a non-blocking state.

  According to the second aspect of the present invention, the rotation suppressing portion that engages with the closed portion of the drain plug in the closed state and suppresses the rotation of the drain plug is provided around the drain hole in the oil pan. Since the protective wall that protects the tool engagement / disengagement part is provided around the drain hole outside the pan, it is possible to prevent the drain plug from unintentionally becoming unoccluded. When it is necessary to do so, the tool can be used to easily and reliably be in a non-closed state.

  According to the third aspect of the invention, the annular wall portion surrounding the closed portion of the drain plug is provided around the drain hole of the oil pan, and the oil drain hole is formed in the vicinity of the base end portion of the annular wall portion. It is possible to prevent oil from remaining in the oil pan when the non-blocking state is achieved.

  According to the fourth invention, the engaging portion and the rotation suppressing portion can be reliably engaged.

It is sectional drawing of the oil pan which concerns on Embodiment 1 of this invention. It is the II-II sectional view taken on the line in FIG. FIG. 3 is a perspective view of the vicinity of a drain hole of the oil pan according to the first embodiment when viewed from below. It is the perspective view which looked at the drain plug which concerns on Embodiment 1 from the side. It is the perspective view which looked at the drain plug which concerns on Embodiment 1 from upper direction. FIG. 3 is a view corresponding to FIG. 2 according to a modification of the first embodiment. It is the perspective view which looked at the drain hole vicinity which concerns on Embodiment 2 from the downward direction. It is the perspective view which looked at the drain plug which concerns on Embodiment 2 from upper direction. It is the perspective view which looked at the drain plug which concerns on Embodiment 2 from the downward direction. It is the XX sectional view taken on the line in FIG. FIG. 9 is a diagram corresponding to FIG. 8 according to Modification 1 of Embodiment 2. FIG. 10 is a diagram corresponding to FIG. 9 according to Modification 1 of Embodiment 2. FIG. 10 is a diagram corresponding to FIG. 10 according to a first modification of the second embodiment. FIG. 9 is a diagram corresponding to FIG. 7 according to a second modification of the second embodiment. FIG. 9 is a diagram corresponding to FIG. 8 according to a second modification of the second embodiment. FIG. 10 is a diagram corresponding to FIG. 9 according to a second modification of the second embodiment. It is the XVII-XVII sectional view taken on the line in FIG. FIG. 9 is a diagram corresponding to FIG. 8 according to Modification 3 of Embodiment 2. FIG. 10 is a diagram corresponding to FIG. 9 according to Modification 3 of Embodiment 2. FIG. 15 is a diagram corresponding to FIG. 14 according to Modification 3 of Embodiment 2. It is the perspective view which looked at the drain hole vicinity which concerns on Embodiment 3 from the upper direction of the oil pan. It is the perspective view which looked at the drain hole vicinity which concerns on Embodiment 3 from the downward direction of an oil pan. 6 is a plan view of the vicinity of a drain hole according to Embodiment 3. FIG. It is a bottom view of the drain hole vicinity which concerns on Embodiment 3. FIG. It is the XXV-XXV sectional view taken on the line in FIG. FIG. 26 is a view corresponding to FIG. 25 in which the drain hole is closed. It is the XXVII-XXVII sectional view taken on the line in FIG. FIG. 28 is a view corresponding to FIG. 27 in which the drain hole is closed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

(Embodiment 1)
FIG. 1 shows an oil pan 1 to which a drain structure of an oil pan according to Embodiment 1 of the present invention is applied. Although not shown, the oil pan 1 is provided at a lower portion of an engine mounted on, for example, an automobile, and is a resin oil pan made entirely of a resin material. In addition to the engine oil pan 1, the present invention can be applied to, for example, an oil pan of an automatic transmission or an oil pan of various machines, although not shown.

  The oil pan 1 includes a bottom wall portion 2, a peripheral wall portion 3 extending upward from the peripheral edge portion of the bottom wall portion 2, and a flange-like fastening plate portion 4 extending outward from the upper end portion of the peripheral wall portion 3. The bottom wall portion 2, the peripheral wall portion 3, and the fastening plate portion 4 are formed by injection molding a resin material. A plurality of bolt insertion holes 4 a are formed in the fastening plate portion 4 at intervals in the circumferential direction of the oil pan 2. A bolt (not shown) is inserted into the bolt insertion hole 4a from below. These bolts are screwed into the lower surface of the engine block, whereby the oil pan 1 is fastened to the engine.

  A drain plug 20 is provided at the bottom of the oil pan 1 (the portion formed by the bottom wall 2 and the lower portion of the peripheral wall 3). A drain hole forming plate part 5 in which a drain hole 10 (shown in FIG. 3) is formed is provided at the bottom of the oil pan 1. The drain hole forming plate portion 5 is formed so as to bulge into the oil pan 1 as a whole.

  The drain hole 10 has a circular cross section and is formed such that its center line A is inclined as shown in FIG. For example, when the left side of FIG. 2 is the front side of the vehicle, the inclination direction of the center line A is a direction that is located upward as it goes to the rear side. When the left side of FIG. It is the direction that is located upward. An annular wall portion 11 is formed around the drain hole 10 in the oil pan 1 so as to protrude in the direction of the center line A. The inner diameter of the annular wall portion 11 is set smaller than the inner diameter of the drain hole 10. The annular wall portion 11 has a cylindrical shape and is located concentrically with the drain hole 10.

  Two threaded claws 11a and 11a projecting radially inward are formed at the distal end in the projecting direction of the annular wall 11 and spaced apart from each other in the circumferential direction. In this embodiment, the screw claws 11a and 11a are arranged so as to face each other. One engaging claw 11a is positioned closer to the projecting direction proximal end side of the annular wall portion 11 than the other screwing claw 11a. This is for screwing into a spiral groove 21a of the drain plug 20 described later.

  Further, in the vicinity of the base end portion of the annular wall portion 11 in the drain hole forming plate portion 5, the oil pan 2 is located upstream of the position where the seal material 23 is assembled (upstream in the oil flow direction when oil is discharged). A plurality of oil drain holes 5 a, 5 a communicating with the drain hole 10 from the inside of the annular wall portion 11 are formed at intervals in the circumferential direction of the annular wall portion 11. The oil drain holes 5 a and 5 a are for discharging oil accumulated near the base end portion of the annular wall portion 11 to the outside of the oil pan 1. In addition, the number of the oil drain holes 5a may be one, and should just be formed in the lower part at least. Further, a step 12f may be provided outside the annular wall portion 11 of the drain hole forming plate portion 5, and by doing so, it becomes possible to easily discharge the oil accumulated outside the annular wall portion 11.

  A small-diameter outer cylindrical portion 12 is formed around the drain hole 10 outside the oil pan 1 so as to protrude in the direction of the center line A. The small-diameter outer tubular portion 12 may be continuous in the circumferential direction or may be partially discontinuous. The outer diameter of the small-diameter outer tubular portion 12 is set to be the same from the base end side portion 12a to the distal end side portion 12b of the small-diameter outer tubular portion 12, while the inner diameter is the same as that of the small-diameter outer tubular portion 12. The distal end side portion 12b is set to be larger than the proximal end side portion 12a. Thereby, the thickness of the small-diameter outer cylindrical portion 12 is thicker in the base end side portion 12a, and a step portion 12c is formed on the inner surface of the small-diameter outer cylindrical portion 12.

  As shown in FIG. 3, the forward end surface 12d of the small-diameter outer cylindrical portion 12 is engaged with the drain plug 20 when the drain plug 20 is in a closed state to suppress the rotation of the drain plug 20. Rotation suppression protrusions (rotation suppression portions) 20e and 20e are formed. The heights of the rotation suppression protrusions 20e and 20e are set so as to gradually increase toward one side in the circumferential direction.

  Around the drain hole 10 outside the oil pan 1, a large-diameter outer cylindrical portion (protective wall portion) 13 is formed outside the small-diameter outer cylindrical portion 12 so as to protrude in the direction of the center line A. . The large-diameter outer cylindrical portion 13 may be continuous in the circumferential direction or may be partially discontinuous. The large-diameter outer cylindrical portion 13 has a cylindrical shape that is located concentrically with the small-diameter outer cylindrical portion 12. The inner diameter of the large-diameter outer tubular portion 13 is set to be larger than the outer diameter of the small-diameter outer tubular portion 12 by a predetermined dimension, and the inner surface of the large-diameter outer tubular portion 13 and the outer surface of the small-diameter outer tubular portion 12 are A gap is formed between them. In addition, the dimension of the large-diameter outer cylindrical portion 13 in the center line A direction is set longer than the dimension of the small-diameter outer cylindrical portion 12 in the center line A direction. Therefore, the protrusion direction front end surface 13a of the large-diameter inner cylindrical portion 13 is positioned outward from the protrusion direction front end surface 12d of the small-diameter outer cylindrical portion 12.

  The drain plug 20 is a resin drain plug formed by injection molding a resin material, and is inserted into the drain hole 10 of the oil pan 1 to close the drain hole 10 as shown in FIGS. 2, 4, and 5. It has the obstruction | occlusion part 21, the tool engagement / disengagement part 22 integrally molded with the obstruction | occlusion part 21, and the sealing material 23. FIG. As shown in FIG. 2, the closed portion 21 is inserted into the drain hole 10, so that the drain hole 10 is positioned inward of the oil pan 1 with respect to the tip of the annular wall portion 11 of the oil pan 1. It is formed in a long column shape in the center line A direction. The distal end portion of the blocking portion 21 (the distal end portion in the insertion direction into the drain hole 10) has a tapered shape. A spiral groove 21 a is formed on the outer surface of the closing portion 21. The screw groove 11a engages with the screwing claws 11a, 11a of the oil pan 1 by entering. The spiral groove 21a is formed so that the drain plug 20 gradually enters the drain hole 10 by turning the drain plug 20 clockwise, that is, a right-hand thread.

  An insertion groove 21b into which a sealing material 23 (shown only in FIG. 2) is fitted is formed at the base end portion (base end portion in the insertion direction into the drain hole 10) of the closing portion 21 rather than the spiral groove 21a. It is formed so as to be continuous over the circumference. The sealing material 23 is a so-called O-ring and is made of an elastic material such as rubber, and is interposed between the closing portion 21 and the inner surface of the drain hole 10 to prevent oil leakage between the two. Further, a hole 21c is formed in the closing part 21. The hole 21 c opens at the distal end surface of the closing part 21 and extends to the proximal end side, and is located on the axis of the closing part 21. When the blocking portion 21 is in a state of closing the drain hole 10, the outer surface of the blocking portion 21 is surrounded by the annular wall portion 11 of the oil pan 1. The closing part 21 is also configured to close the oil drain holes 5a and 5a.

  The tool engagement / disengagement portion 22 is integrally formed on the proximal end side of the closing portion 21 and is provided so as to have a larger diameter than the portion where the insertion groove 21b of the closing portion 21 is formed so as to face the outside of the oil pan 1. ing. A tool insertion hole 22b for inserting a tip of a tool (not shown) is formed in a surface 22a facing the outside of the oil pan 1 in the tool engagement / disengagement portion 22. The cross-sectional shape of the tool insertion hole 22b may be, for example, a hexagon or a quadrangle, and may be a shape that substantially matches the outer shape of the tool and does not idle.

  The tool engagement / disengagement portion 22 is formed with a flange 24 protruding outward in the radial direction. The flange 24 is circular as shown in FIG. The outer diameter of the flange 24 is set smaller than the inner diameter of the large-diameter outer tubular portion 13. In a state where the drain plug 20 closes the drain hole 10, the flange 24 is positioned on the proximal end side with respect to the distal end surface 13 a of the large-diameter outer tubular portion 13, and the large-diameter outer tubular portion 13 covers the outer peripheral surface of the flange 24. It will be enclosed. At this time, a gap is formed between the outer peripheral surface of the flange 24 and the inner surface of the large-diameter outer cylindrical portion 13. Further, a portion of the tool engaging / disengaging portion 22 closer to the closing portion 21 than the flange 24 is arranged inside the small-diameter outer cylindrical portion 12.

  As shown in FIGS. 4 and 5, engagement recesses (engagement portions) 24b and 24b that engage with the rotation suppression protrusions 20e and 20e are formed on the surface 24a of the flange 24 that faces the oil pan 1 around each other. It is provided at intervals in the direction. Although not shown, the engagement recess may be provided on the bottom wall 2 of the oil pan 1 and the rotation suppression protrusion may be provided on the surface 24 a of the flange 24 facing the oil pan 1.

  The engagement recesses 24b and 24b are formed so as to become deeper toward the one side in the circumferential direction so as to correspond to the change in the projection height in the circumferential direction of the rotation suppressing projections 20e and 20e. Thereby, each rotation suppression protrusion 20e comes to fit securely in the engagement recess 24b.

  Next, the case where the drain hole 10 of the oil pan 1 configured as described above is closed by the drain plug 20 will be described. First, a tool is inserted into the tool insertion hole 22b of the drain plug 20, and the distal end portion of the drain plug 20 is inserted into the drain hole 10. In this state, the drain plug 20 is rotated to the right. Then, the drain plug 20 rotates around the center line A of the drain hole 10, and at this time, the screwing claws 11a and 11a enter and engage with the spiral groove 21a of the drain plug 20, so that the shape of the spiral groove 21a Thus, the drain plug 20 is inserted into the drain hole 10. When the drain plug 20 is completely inserted into the drain hole 10, the drain hole 10 is closed. In the closed state, the closed portion 21 closes the oil drain holes 5 a and 5 a, and the sealing material 23 seals between the closed portion 21 and the inner surface of the drain hole 10. At this time, since each rotation suppression protrusion 20e fits into the engagement recess 24b, the rotation is reliably suppressed when the drain plug 20 attempts to rotate leftward. Therefore, oil leakage can be suppressed.

  In the closed state, the portion of the tool engagement / disengagement portion 22 closer to the closing portion 21 than the flange 24 is disposed inside the small diameter outer cylindrical portion 12, and the large diameter outer cylindrical portion 13 protects the flange 24. Thus, it extends so as to surround the flange 24. For this reason, for example, when an obstacle such as a stone flies, the obstacle hardly hits the tool engagement / disengagement portion 22 and its flange 24, and therefore, damage to the tool engagement / disengagement portion 22 and its flange 24 can be suppressed. .

  On the other hand, when the drain plug 20 in the closed state is rotated to the left, the drain plug 20 moves in the direction of coming out of the drain hole 10 and becomes a non-closed state. That is, the drain plug 20 rotates around the center line A of the drain hole 10 and is switched between a closed state and a non-closed state. When switching to the non-blocking state, a large torque is applied by a tool, so that the rotation suppressing protrusion 20e comes out of the engagement recess 24b and the drain plug 20 can be rotated. The oil inside the oil pan 1 flows out from the drain hole 10 and also flows out from the oil drain hole 5a, so that it is difficult for the oil to remain inside the oil pan 1.

  As described above, according to the drain structure of the oil pan 1 according to the first embodiment, the tool engagement / disengagement portion 22 of the drain plug 20 is provided so as to face the outside of the oil pan 1, so that the tool can be used as a tool. The drain plug 20 can be rotated by being easily engaged with the engaging / disengaging portion 22. When the drain plug 20 is closed, the tool engagement / disengagement portion 22 of the drain plug 20 engages with the rotation restraining protrusion 20e of the oil pan 1, so that the rotation of the drain plug 20 can be suppressed. At this time, since the tool engagement / disengagement portion 22 is protected by the large-diameter outer cylindrical portion 13, for example, an obstacle or the like hardly hits the tool engagement / disengagement portion 22, and damage to the tool engagement / disengagement portion 22 can be prevented. Therefore, the drain plug 20 can be maintained in a state of being engaged with the large-diameter outer cylindrical portion 13, and the drain plug 20 can be prevented from being in a non-closed state.

  On the other hand, when the drain plug 20 is switched from the closed state to the non-closed state, the tool engagement / disengagement portion 22 is protected as described above. You can switch to the state.

  Moreover, the drain hole 10 can also be provided in the bottom wall part 2 of the oil pan 1 like the modification of Embodiment 1 shown in FIG. In this case, the center line A of the drain hole 10 extends in the vertical direction. Further, the closing portion 21 of the drain plug 20 has a column shape extending in the vertical direction.

(Embodiment 2)
7 to 10 relate to Embodiment 2 of the present invention. In Embodiment 2, the small-diameter outer cylindrical portion 12 is omitted and the annular wall portion 11 is extended, and the rotation suppression protrusions (rotation suppression portions) 2 a and 2 a are connected to the bottom wall portion 2 of the oil pan 1. This is different from that of the first embodiment in that it is provided on the outer surface of the first embodiment. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and different parts will be described in detail.

  As shown in FIG. 10, the drain plug 20 is engaged with the tool engagement / disengagement portion 22 when the drain plug 20 is in a closed state around the drain hole 10 on the outer surface of the bottom wall portion 2 of the oil pan 1. The rotation suppression protrusions 2a and 2a that suppress the rotation of are provided at intervals in the circumferential direction. Similar to the rotation suppression protrusions 20e and 20e of the first embodiment, the rotation suppression protrusions 2a and 2a are formed such that the protrusion height increases as going to one side in the circumferential direction.

  The annular wall portion 11 is extended in the protruding direction as compared with the first embodiment. As a result, a sufficient sealing surface with the sealing material 23 can be secured, the closed portion 21 of the drain plug 20 can be held by the annular wall portion 11, and the drain plug 20 can be stabilized. By providing slits (notches) 24k, 24k between the recesses 24b, 24b of the flange 24 and the tool engagement / disengagement portion 22, it is possible to easily engage / disengage using the tool while reliably suppressing loosening of the drain plug 20. To be able to.

  According to the drain structure of the oil pan 1 according to the second embodiment, as in the first embodiment, the rotation of the drain plug 20 can be suppressed, and the tool engagement / disengagement portion 22 has the large-diameter outer tubular portion 13. Therefore, the breakage of the tool engagement / disengagement part 22 can be prevented. Therefore, the drain plug 20 can be maintained in a state of being engaged with the large-diameter outer cylindrical portion 13, and the drain plug 20 can be prevented from being in a non-closed state. Further, when the drain plug 20 is switched from the closed state to the non-closed state, the tool can be reliably engaged with the tool engagement / disengagement unit 22 and switched to the non-closed state.

  Further, as in Modification 1 of Embodiment 2 shown in FIGS. 11 to 13, a protrusion 26 is provided in the tool engagement / disengagement portion 22 of the drain plug 20, and a tool insertion hole 26 b is formed in the protrusion 26. Good.

  Moreover, you may provide the stoppers 2b and 2b for preventing the drain plug 20 from overtightening like the modification 2 of Embodiment 2 shown in FIGS. The stoppers 2b and 2b protrude from the periphery of the drain hole 10 on the outer surface of the bottom wall portion 2 of the oil pan 1, and are positioned between the rotation suppression protrusions 2a and 2a.

  On the other hand, as shown in FIGS. 15 and 17, the flange 24 of the drain plug 20 is provided with convex portions 24 d and 24 d so as to be positioned between the engagement concave portions 24 b and 24 b. Accordingly, when the drain plug 20 is rotated to the right, the stoppers 2b and the convex portions 24d approach each other in the circumferential direction, and eventually come into contact with each other to stop the rotation of the drain plug 20. As a result, overtightening of the drain plug 20 can be prevented. The number of stoppers 2b and convex portions 24d may be one.

  Further, as in Modification 3 of Embodiment 2 shown in FIGS. 18 to 20, a protrusion 26 is provided in the tool engagement / disengagement portion 22 of the drain plug 20 on the assumption of the configuration of Modification 2, and a tool is provided in the protrusion 26. The insertion hole 26b may be formed.

(Embodiment 3)
21 to 27 relate to Embodiment 3 of the present invention. The third embodiment is different from the first and second embodiments in that the drain plug 20 is engaged with the inside of the oil pan 1. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and different parts will be described in detail.

  In the third embodiment, an annular wall portion 11 is formed around the drain hole 10 in the oil pan 1, and the annular wall portion 11 opens toward the inside of the annular wall portion 11. Guide grooves 11b, 11b extending in the center line direction are formed at intervals in the circumferential direction. Both ends of the guide grooves 11b and 11b in the longitudinal direction are open.

  Concave portions (rotation suppressing portions) 11c and 11c are formed on the front end surface of the annular wall portion 11 in the protruding direction. The recesses 11c and 11c are positioned between the guide grooves 11b and 11b. Further, stopper surfaces 11d and 11d extending in the protruding direction of the annular wall portion 11 are continuous with the inner surfaces of the recesses 11c and 11c. Furthermore, lock projections 11e and 11e are formed adjacent to the recesses 11c and 11c. Further, reverse rotation preventing protrusions 11f and 11f are formed adjacent to the guide grooves 11b and 11b.

  On the other hand, pin-shaped portions 29 and 29 projecting in the radial direction are formed at the distal end portion of the closing portion 21 of the drain plug 20 at intervals in the circumferential direction. The pin-shaped portions 29 and 29 are inserted into the guide grooves 11b and 11b of the oil pan 1, respectively.

  In the third embodiment, the pin-shaped portions 29 and 29 of the drain plug 20 are inserted into the guide grooves 11b and 11b and guided to the front end side in the protruding direction of the annular wall portion 11 by the guide grooves 11b and 11b. When the drain plug 20 is rotated to the right when viewed from below, the pin-shaped portions 29 and 29 move in the circumferential direction on the front end surface of the annular wall portion 11 in the protruding direction. At this time, if it is attempted to rotate in the reverse direction (left direction), the pin-shaped portions 29 and 29 will come into contact with the reverse rotation preventing protrusions 11f and 11f, thereby preventing reverse rotation.

  When the drain plug 20 is rotated until the pin-shaped portions 29, 29 get over the locking projections 11e, 11e and enter the recesses 11c, 11c, the pin-shaped portions 29, 29 become the locking projections 11e, 11e and the stopper. The surfaces 11d and 11d stay in the recesses 11c and 11c, whereby the recesses 11c and 11c engage with the pin-shaped portions 29 and 29 of the closing portion 21 to suppress the rotation of the drain plug 20. The drain plug 20 is closed.

  On the other hand, when the drain plug 20 in the closed state is rotated to the left, the pin-shaped portions 29, 29 get over the locking projections 11e, 11e and come out of the recesses 11c, 11c to release the engaged state. Then, after the pin-shaped portions 29 and 29 of the drain plug 20 are aligned with the guide grooves 11b and 11b, the drain plug 20 is brought into a non-blocking state when the drain plug 20 is moved downward.

  In the third embodiment, when the drain plug 20 is closed, the pin-shaped portions 29 and 29 of the closing portion 21 of the drain plug 20 are engaged with the recesses 11c and 11c, so that the rotation of the drain plug 20 is suppressed. . At this time, since the pin-shaped portions 29 and 29 are portions to be inserted into the drain hole 10, no obstacle or the like hits them. Therefore, the pin-shaped portions 29 and 29 are prevented from being damaged, and the drain plug 20 Can be prevented from becoming unblocked. In addition, since the tool engagement / disengagement portion 22 is protected by the large-diameter outer tubular portion 13, for example, an obstacle or the like is less likely to hit the tool engagement / disengagement portion 22 and its flange 24. Damage can be prevented.

  In the second and third embodiments, the drain hole 10 may be provided near the lower portion of the peripheral wall 3 of the oil pan 1 as in the first embodiment. In the first to third embodiments, the slit (notch portion) 24k of the second embodiment can be provided. Also in the third embodiment, the step 12f of the first embodiment can be provided.

  The above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the drain structure of the oil pan according to the present invention can be applied to, for example, a resin oil pan provided in an engine.

1 Oil pan 2 Bottom wall (outside of oil pan)
2a Rotation suppression protrusion (rotation suppression part)
5a Oil drain hole 10 Drain hole 11 Annular wall part 11c Concave part (rotation suppression part)
13 Large-diameter outer cylindrical part (protective wall part)
20 Drain plug 20e Rotation suppression protrusion (rotation suppression portion)
21 Closure part 22 Tool engagement / disengagement part 23 Seal material 24 Flange 24b Engagement recess (engagement part)

Claims (4)

In the drain structure of the oil pan (1) in which the drain hole (10) formed in the bottom of the resin oil pan (1) is closed by the resin drain plug (20),
The drain plug (20) is inserted into the drain hole (10) so as to close the drain hole (10), a columnar blocking part (21), A tool engagement / disengagement unit provided to face the outside of the oil pan (1) and a tool for rotating the drain plug (20). (22) and rotating around the center line of the drain hole (10) to switch between a closed state and a non-closed state,
Around the drain hole (10) outside the oil pan (1), the drain plug (20) engages with the tool engagement / disengagement part (22) when the drain plug (20) is in the closed state. Rotation restraining portions (2a, 20e) for restraining the rotation of (20) and a protective wall portion (13) extending so as to surround the tool engaging / disengaging portion (22) and protecting the tool engaging / disengaging portion (22). And a drain structure of the oil pan (1). In the drain structure of the oil pan (1) in which the drain hole (10) formed in the bottom of the resin oil pan (1) is closed by the resin drain plug (20),
The drain plug (20) is inserted into the drain hole (10) to close the drain hole (10), a columnar blocking part (21), the blocking part (21), and the drain hole (10) A tool engagement / disengagement unit provided to face the outside of the oil pan (1) and a tool for rotating the drain plug (20). (22) and rotating around the center line of the drain hole (10) to switch between a closed state and a non-closed state,
Around the drain hole (10) in the oil pan (1), when the drain plug (20) is in the closed state, the drain plug (20) is engaged with the closed portion (21). ) Is provided with a rotation suppressing portion (11c) for suppressing the rotation of
A protective wall (13) that extends around the drain hole (10) outside the oil pan (1) so as to surround the tool engagement / disengagement portion (21) and protects the tool engagement / disengagement portion (21). The drain structure of the oil pan (1), wherein In the drain structure of the oil pan (1) according to claim 1 or 2,
Around the drain hole (10) of the oil pan (1), an annular wall portion (11) extending so as to surround the closing portion (21) of the drain plug (20) is provided in the oil pan (1). Provided to protrude inside,
An oil drain hole (5a) that opens upstream from the sealing material (23) is formed in the vicinity of the base end of the annular wall (11). Construction. In the drain structure of the oil pan (1) according to claim 1,
A flange (24) is formed on the tool engagement / disengagement part (22) of the drain plug (20),
At least one of the outer surface (2) of the oil pan (1) and the surface (24a) of the flange (24) facing the outer surface (2) of the oil pan (1) is provided with the rotation suppressing portion ( 2a, 20e), and the drain structure of the oil pan (1), wherein the other is provided with an engaging portion (24b) that engages with the rotation suppressing portion (2a, 20e).

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