JP5412493B2 - Removal prevention cover and fuel pressure sensor unit provided with the same - Google Patents

Description

  The present invention relates to a removal prevention cover for a fastening member that includes a head whose outer peripheral surface forms a tool engagement surface and is attached to a fastened portion, and a fuel pressure sensor unit including the same.

  As various parts attached to the internal combustion engine, there are those in which a screwing portion for screw fastening is formed and fastened to a predetermined fastening position (fastened portion) by applying rotational torque with a tool. Some of these parts are inconvenient if removed or rotated by the user.

  For example, a distributor that adjusts the ignition timing of the internal combustion engine is rotatably attached to the internal combustion engine by a fastening member such as a nut or a bolt, and is fixed by the fastening member at a rotational position that has adjusted the ignition timing. Therefore, if the user loosens the fastening member, the distributor rotates from the initially set position and the ignition timing changes, which is not preferable. Therefore, in order to prevent the user from rotating the nut that fixes the distributor, an invention has been proposed in which a cylindrical removal prevention cover is pressed against the nut and attached, and the outer periphery of the nut is covered by the removal prevention cover. (Patent Document 1). In the present invention, a plurality of claws projecting radially inward are provided at the opening end of the cylindrical wall constituting the member main body in the pressing direction side so that the removal preventing cover does not come off the nut. Thereby, even if a user tries to remove a nut, a tool cannot be engaged with a nut and it is prevented that a nut is loosened.

Japanese Utility Model Publication No. 60-6624

  However, in the invention of Patent Document 1, since the claw is provided on the cylindrical wall of the removal prevention cover, it is possible to easily release the engagement of the claw by deforming the cylindrical wall outward in the radial direction. There is a possibility that the removal prevention cover may be detached from the fastening member.

  When the removal prevention cover is applied to the fastening member that fixes the rotational position of the distributor as in Patent Document 1, even if the user loosens the fastening member accidentally and changes the ignition timing of the internal combustion engine, The pivot position of the distributor can be adjusted again. However, some fastening members, such as a fuel pressure sensor, plastically deform one of the screwed portion and the screwed portion of the fastened portion during attachment. When the fastening member is a fuel sensor having such an attachment structure, if the fastening member is loosened even once after attachment, the sealing performance cannot be secured even if the fastening member is tightened again, and fuel leakage or As a result, the emission is reduced due to the deterioration of controllability and the fuel consumption is deteriorated. Therefore, there is a need for a removal prevention cover that can reliably prevent the user from removing (loosing) the fastening member after shipment.

  The present invention has been devised to solve the problems included in the prior art, and an object thereof is to provide a removal prevention cover that can reliably prevent a user from removing a fastening member.

  In order to solve such a problem, according to one aspect of the present invention, a threaded part (male thread part 11) that is threadedly engaged with a fastened part (6) and an outer peripheral surface that are integrally formed with the threaded part. Is a removal prevention cover (20) for a fastening member (10) provided with a head (12) forming a tool engaging surface, and a cylindrical cover body (21) covering the outer peripheral surface of the head And a base end (22a) protruding from the inner surface (21a) of the cover main body portion, and a free end extending toward the fastened portion side in the axial direction of the cover main body portion with a gap between the inner end (22a) and the inner surface A plurality of first protrusions (22) having (22b) and the free ends of the first protrusions are formed so as to protrude inward in the radial direction of the cover main body, and engage with the head. It is set as the structure provided with the engagement nail | claw (23).

  According to this configuration, since the engaging claw is formed on the first projecting piece provided inside the cover main body, even if the cover main body is deformed radially outward, the head of the engaging claw Will not be released, and the removal prevention cover will not be detached once it is attached to the head. Therefore, it is possible to reliably prevent the user from removing the fastening member. When the removal prevention cover is attached to the fastening member, since there is a gap between the inner surface of the cover main body and the free end of the first projecting piece, it is only pressed with a force that elastically deforms the first projecting piece. It's okay.

  Further, according to one aspect of the present invention, the engagement claw has an engagement surface (23a) that faces an end surface (12a) of the head portion on the fastened portion side, and the cover body portion has the engagement surface (23a). The end edge (21b) on the fastened part side can be configured to be positioned closer to the fastened part side than the engagement surface.

  According to this configuration, in the state where the engaging claw is engaged with the head, the end edge of the cover body portion on the fastened portion side is located closer to the fastened portion side than the end surface of the head on the fastened portion side, Since the outer periphery of the head is completely covered with the cover body, it is possible to reliably prevent the removal prevention cover from being detached and the fastening member from being removed by the user.

  Further, according to one aspect of the present invention, the cover main body portion is formed so as to protrude radially inward of the cover main body portion on the side opposite to the fastened portion side, and the engaging claw is In a state of being engaged with the head portion, a second projecting piece (24) that abuts on an end edge (12b) on the side opposite to the fastened portion in the head portion can be provided.

  According to this configuration, since the removal prevention cover sandwiches the head between the engagement claw and the second projection piece of the first protrusion, it is possible to prevent the removal prevention cover from rattling.

  Further, according to one aspect of the present invention, the fuel pressure in the fuel supply pipe is attached to the fuel supply pipe (6) for pumping fuel to the fuel injection valve (6) attached to the internal combustion engine (E). A fuel pressure sensor unit (7) provided with a fuel pressure sensor (10) for detecting fuel and a removal prevention cover (20) having the above-described configuration, wherein the head is provided on the fuel pressure sensor. .

  According to this configuration, even when the fuel pressure sensor is attached to the fuel supply pipe by plastically deforming one of the screwing part and the screwing part of the fuel supply pipe, the removal prevention cover is surely removed. Therefore, it is possible to prevent the occurrence of fuel leakage or the like due to the removal of the fuel pressure sensor by the user. Further, when fuel leakage occurs at the attachment portion of the fuel pressure sensor, it is possible to easily determine whether or not it is caused by the removal of the fuel pressure sensor by looking at the damaged state of the removal prevention cover.

  Thus, according to the present invention, it is possible to provide a removal prevention cover that can reliably prevent the user from removing the fastening member.

Lumbar perspective view of fuel pressure supply system according to an embodiment 1 is an exploded perspective view of the fuel pressure sensor unit shown in FIG. Bottom view of the removal prevention cover shown in FIG. IV-IV sectional view in FIG. VV sectional view in FIG. Sectional drawing corresponding to FIG. 4 of the removal prevention cover which concerns on a modification

  Hereinafter, embodiments of the removal prevention cover 20 and the fuel pressure sensor unit 8 according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a fuel supply device 1 is attached to an in-line four-cylinder gasoline engine (hereinafter simply referred to as an engine E) having four intake passages 2. The fuel supply device 1 includes a high-pressure fuel pump 3, a fuel supply pipe 4 connected to the high-pressure fuel pump 3, one end 6 a of which is connected to the downstream end of the fuel supply pipe 4 via a connector 5, and the fuel supply pipe 4. A delivery pipe 6 having a larger inner diameter and extending in the cylinder arrangement direction of the engine E, and four fuel injection valves 7 provided for each cylinder along the extension direction of the delivery pipe 6, And a fuel pressure sensor unit 8 provided at the other end 6b of the delivery pipe 6.

  As shown in FIG. 2, the fuel pressure sensor unit 8 is coaxial with a male screw portion 11 that is screwed into the other end 6 b of the delivery pipe 6 and one end in the axial direction of the male screw portion 11 (one end opposite to the delivery pipe 6). A fuel pressure sensor 10 having an integrally formed hexagonal column-shaped head 12 and a coupler 13 formed so as to protrude from the end surface of the head 12 opposite to the male screw portion 11, and removal of the fuel pressure sensor 10 And an anti-removal cover 20 for preventing the above. It should be noted that the coupler 9 of the fuel pressure sensor 10 is provided with a harness 9 (bundled with a wire for supplying power to the fuel pressure sensor 10 and a signal line for taking out a signal from the fuel pressure sensor 10 after the removal prevention cover 20 is attached. Are connected).

  The male screw portion 11 is formed in a cylindrical shape, and accommodates therein a sensor element (not shown) that detects fuel pressure, and has a tapered shape that tapers from the head 12 side toward the tip. Here, the head 12 has the same function as the bolt head of the hexagonal bolt, that is, in order to give a rotational torque to the male screw portion 11, its outer peripheral surface forms a tool engagement surface that is engaged by a tool. When rotational torque is applied to the head 12, the male screw portion 11 is screwed with the other end 6 b of the delivery pipe 6 while plastically deforming the inner peripheral surface of the delivery pipe 6. Thereby, the fuel pressure sensor 10 is attached to the delivery pipe 6 with high sealing performance.

  The removal prevention cover 20 is an injection-molded product made of resin, and has a cylindrical cover body 21 that can receive the head 12 as shown in FIGS. 3 and 4. In the following description, for the sake of convenience, the vertical direction is specified with reference to the vertical direction in FIG. The cover main body 21 is formed along the axis 21x of the cover main body 21 with a gap 25 between the inner end 21a and a base end 22a protruding radially inward from an intermediate position in the axial direction on the inner surface 21a. A plurality (six in this case) of first projecting pieces 22 having a free end 22b extending to the lower surface side (delivery pipe 6 side) are integrally formed. An engaging claw 23 that projects inward in the radial direction of the cover main body 21 is formed integrally with the free end 22 b of each first protrusion 22. Further, a second projecting piece 24 is integrally formed at the upper end of the cover main body portion 21 so as to be curved inward in the radial direction.

  The engaging claw 23 extends upward in a direction substantially perpendicular to the axis 21x of the cover main body 21 and faces upward, and is inclined downward toward the outer side in the radial direction of the cover main body 21 and goes downward. And a lower surface 23b facing. Here, the second projecting piece 24 has a dome shape in which the tip edge forms a circular opening 26. For convenience of molding, slits 27 as indicated by broken lines in FIG. 3 may be formed at appropriate positions in the circumferential direction with respect to the second projecting piece 24 in order to facilitate die cutting.

  As shown in FIG. 5, the inner diameter D <b> 1 of the cover main body 21 is slightly larger than the maximum diameter e of the head 12 (the diameter of a circle circumscribing the head 12). On the other hand, as shown in FIG. 4, the separation distance L1 between each pair of first protrusions 22 arranged on the diameter of the cover main body 21 is the minimum diameter s of the head 12 (a circle inscribed in the head 12). Is equivalent to the diameter). Therefore, in a state where the removal prevention cover 20 is not attached to the head 12, the separation distance L 2 between the tips of the pair of engaging claws 23 arranged on the diameter of the cover main body 21 is the maximum of the head 12. It is smaller than the small diameter s. Further, the protruding dimension L3 of the engaging claw 23 is approximately the same as that of the gap 25. The cover main body 21 extends such that a lower end edge 21b (end edge on the delivery pipe 6 side) is positioned below the engagement surface 23a (delivery pipe 6 side).

  After the fuel pressure sensor 10 is attached to the delivery pipe 6, the removal prevention cover 20 is attached to the head 12 by pressing the engagement claw 23 against the head 12. When the removal prevention cover 20 is pushed in, the first projecting piece 22 is elastically deformed radially outward so as to reduce the gap 25 around the base end 22a connected to the cover main body 21, and the engaging claw 23 is moved to the head. 12 is brought into sliding contact with the outer peripheral surface. When the engaging claw 23 passes the outer peripheral surface of the head 12, the first protruding piece 22 returns to the original position, and the engaging claw 23 engages with the head 12. Then, the engaging surface 23a of the engaging claw 23 faces the lower end surface 12a of the head 12 (end surface on the male screw portion 11 side).

  In a state where the engaging claw 23 is engaged with the head 12, the engaging surface 23 a of the engaging claw 23 extends substantially orthogonal to the axis 21 x of the cover main body 21, and the lower end surface of the head 12 Opposite parallel to 12a. Thereby, the removal prevention cover 20 is not detached from the head 12 even when pulled upward. Therefore, if the user forcibly removes the removal prevention cover 20, the removal prevention cover 20 is damaged. In the state where the engaging claw 23 is engaged with the head 12, the cover main body 21 accommodates the head 12 and completely covers the outer peripheral surface of the head 12, and as shown in FIG. The projecting piece 24 elastically contacts the upper end edge 12b of the head 12 (the end opposite to the delivery pipe 6), and the lower end surface 12a of the head 12 is engaged with the engaging surface 23a of the engaging claw 23. It is made to contact.

  According to the removal preventing cover 20 configured as described above, the engaging claw 23 is formed on the first projecting piece 22 provided on the inner side of the cover main body 21, so that the cover main body 21 is deformed radially outward. Even if it makes it, engagement with the engagement nail | claw 23 and the head 12 is not cancelled | released, and it can prevent reliably that the removal prevention cover 20 once mounted | worn is removed by the user.

  Further, since the engaging surface 23 a is arranged above the lower end edge 21 b of the cover main body portion 21, the lower end edge 21 b of the cover main body portion 21 is in a state where the engaging claw 23 is engaged with the head 12. Since it is located below the lower end surface 12a of the head 12 and the outer periphery of the head 12 is completely covered by the cover body 21, the user can reliably prevent the fuel pressure sensor 10 from being removed. The lower end of the engaging claw 23 or the free end 22 b of the first projecting piece 22 protrudes downward from the lower end edge 21 b of the cover main body 21, but the engaging surface 23 a is positioned inside the cover main body 21. In addition, since the lower surface 23b of the engaging claw 23 is inclined, it is not easy to remove the removal prevention cover 20 from the head 12.

  Since the fuel pressure sensor unit 8 includes the removal prevention cover 20, the user can be prevented from removing the fuel pressure sensor 10, so that the fuel pressure sensor 10 connects one of the male screw portion 11 and the inner surface of the delivery pipe 6 as described above. The effect of preventing the fuel pressure sensor 10 from being removed is great when it is plastically deformed and attached to the delivery pipe 6. Further, even if fuel leakage occurs at the attachment portion of the fuel pressure sensor 10, whether the fuel leakage is caused by the removal of the fuel pressure sensor 10 by seeing the damaged state of the removal prevention cover 20 on the manufacturer side. It is possible to easily determine whether or not.

  Further, since the second projecting piece 24 is formed at the upper end of the cover main body 21, the removal preventing cover 20 is elastically held between the engaging claw 23 and the second projecting piece 24 of the first projecting piece 22. Since it is attached to the head 12 in a state, rattling of the removal prevention cover 20 due to vibration of the engine E or the like is prevented.

<Modification>
Next, a modified example of the removal preventing cover 20 will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the member which has the same structure or function as the said embodiment, and the overlapping description is abbreviate | omitted. As shown in FIG. 6, in the removal prevention cover 20 of the present modification, the lower ends of the first projecting pieces 22 and the engaging claws 23 are located above the lower end edge 21 b of the cover main body 21. . With this configuration, once the removal prevention cover 20 is attached to the fuel pressure sensor 10, the first projecting piece 22 and the engaging claw 23 cannot be seen even when viewed from the direction perpendicular to the axis of the cover body 21. It can prevent more reliably that the sensor 10 is removed by the user.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above embodiment, the fuel pressure sensor unit 8 according to the present invention is applied to an in-line four-cylinder gasoline engine, but it is also possible to apply it to other internal combustion engines. Moreover, in the said embodiment, although the removal prevention cover 20 which concerns on this invention was applied to the fuel pressure sensor 10, it is also possible to apply to another fastening member. Moreover, in the said embodiment, although the head 12 of the fuel pressure sensor 10 was made into the hexagonal column shape, it can also be set as other shapes, such as a triangular prism and a quadratic prism shape. In the above embodiment, six first protrusions 22 are formed in accordance with the number of outer peripheral surfaces of the head 12, but three or two are arranged at equal intervals or unequal intervals, or four or five. It is also possible to arrange them at unequal intervals. In addition, the specific configuration, arrangement, and quantity of the units and members can be changed as appropriate without departing from the spirit of the present invention. On the other hand, not all the constituent elements of the fuel pressure sensor unit 8 and the removal prevention cover 20 according to the present invention shown in the above embodiment are necessarily essential, and can be appropriately selected as long as they do not depart from the gist of the present invention. It is.

6 Delivery pipe (fuel supply pipe)
7 Fuel injection valve 8 Fuel pressure sensor unit 10 Fuel pressure sensor 11 Screw part 12 Head 12a Lower end surface of the head 12 (end surface on the delivery pipe 6 side)
12b Upper end edge of head 12 (end edge opposite to delivery pipe 6)
20 prevention cover 21 cover main body part 21a inner surface of cover main body part 21b end edge of cover main body part 21 on delivery pipe 6 side 22 first projecting piece 22a base end of first projecting piece 22b free end of first projecting piece 22 23 engaging claw 23a engaging surface 24 second projecting piece 25 gap E engine

Claims (4)

A detachment prevention cover for a fastening member, comprising: a screwed portion that is screwed into a fastened portion; and a head that is formed integrally with the screwed portion and has an outer peripheral surface that forms a tool engaging surface.
A cylindrical cover body covering the outer peripheral surface of the head;
A plurality of first protrusions having a base end protruding from the inner surface of the cover body portion and a free end extending toward the fastened portion side with a gap between the inner surface and the inner surface;
An anti-detachment cover comprising an engaging claw that is formed to protrude radially inward of the cover main body at the free end of the first projecting piece and engages the head. The engaging claw has an engaging surface facing the end surface of the head on the side to be fastened,
The removal prevention cover according to claim 1, wherein an end edge of the cover main body on the side of the fastened part is located on the side of the fastened part with respect to the engagement surface.   In the state where the cover main body portion is formed so as to protrude radially inward of the cover main body portion on the side opposite to the fastened portion side, and the engagement claw is engaged with the head, The removal prevention cover according to claim 1 or 2, further comprising a second projecting piece that abuts against an edge of the head opposite to the portion to be fastened. A fuel pressure sensor that is attached to a fuel supply pipe for pumping fuel to a fuel injection valve attached to the internal combustion engine and detects the fuel pressure in the fuel supply pipe, and a removal prevention cover according to claim 1 or claim 2. A fuel pressure sensor unit comprising:
A fuel pressure sensor unit, wherein the head is provided in the fuel pressure sensor.

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