WO1999051860A1 - Oil drain plug of engine - Google Patents

Abstract

A new type of plug incorporating a normally closed valve for draining oil from an oil pan of a car engine, wherein the normally closed valve is incorporated in a through hole (113) provided as an oil draining path in a bolt type member (11) fixed to the oil pan (102), an oil draining dedicated jig (7) is assembled to the plug so as to open the normally closed valve in order to drain the oil contained in the oil pan (102) by sucking it with a negative pressure, a movable valve disc member (13) installed in the through hole (113) is installed so that it is engaged with a valve seat (121) provided near the outer end part of the through hole (113) by a coiled spring (14) so as to form the normally closed valve, and the tip end of the plug is made flush generally with the internal surface of the oil pan so as to prevent any structure from projecting toward the inside.

Description

 Specification

 Engine oil drain plug Technical field

 The present invention relates to an oil drain plug used for an oil pan of an automobile engine. Background art

 Conventionally, automobile engines are provided with a mechanism that circulates lubricating oil (oil) at a predetermined location in order to smoothly move the operating parts. However, this oil deteriorates over time with use and the desired lubrication performance is obtained. Can not be obtained, and wear powder and sludge are mixed in the oil. For this reason, old oil is replaced at regular intervals (generally every travel of a constant distance of about 300 to 500 km) from the viewpoint of preventing damage to the engine body.

FIG. 5 is a view for explaining an example of a conventional general engine having a structure for replacing the old oil. The oil pan 102 provided at a lower portion of the crankcase is provided with an oil 1. 00 is supplied to a predetermined portion by an oil pump 101. Oil is pumped by pump 101 and pressure is adjusted by regulating valve 103. Then, foreign matter such as metal powder, bonbon and sludge mixed in oil is removed by filter 104 and cleaned. The oil that has lubricated each part of the engine is provided so as to return to the oil pan 102 again. The oil pan 102 usually has a structure that is always filled with oil. As described above, the oil is normally subjected to a cleaning process of removing contaminants by the filter 104 in the middle of the circulation, but not only is there a limit to the removal of foreign substances by the filter, but the oil itself deteriorates in performance over time. The problem is inevitable. Therefore, the plug (drain cock) 106 was removed from the normally closed oil drain hole (drain hole) 105 provided at the bottom of the oil pan 102, and the old oil was drained by gravity. Next, the oil is exchanged by closing the oil drain hole 105 and pouring new oil from above. However, the above oil change operation is a troublesome work in which the plug is removed from the oil drain hole 105 at the beginning of the operation, and the plug is screwed in after the oil is drained, and the operator is prevented from being covered with oil. I can't.

 Therefore, an operation of extracting oil from the upper side of the engine is also being performed. For example, a method in which a long and thin suction tube is inserted into the mounting hole of the oil gauge provided to check the oil level and dirt of the engine, and vacuum suction of old oil is performed, or a method in which the suction tube is inserted through the oil injection port These are referred to as “up-drawing methods”).

 In these methods, the top end of the tube reaches the bottom of the oil pan because the tube is inserted from above a crank shaft or other complicated mechanism contained in a compact space. There is no way to confirm that it is difficult to remove the entire amount of old oil. Work may be required. In addition, it is difficult to remove metal powder and the like deposited on the bottom of the oil pan, and it is not always widely used.

 On the other hand, a method of removing old oil has been proposed, which can remove the entire amount of oil, while taking advantage of this advantage and eliminating difficulties such as oil contamination. For example, an oil changing method using a permanent fixing plug (plug) with a built-in normally closed type port valve (US Pat. No. 4,745,984 (corresponding Japanese gazette: Japanese Patent Publication No. 4-48988) No. 7)), and an oil change method using a permanently fixed plug (plug) with a built-in normally closed ball valve (Japanese Patent Application Laid-Open No. Hei 8-17082).

These methods involve removing the existing simple plug-shaped oil drain hole plug 106 shown in Fig. 5 and replacing it with a valve plug (not shown) with a built-in normally closed valve. It is used by fixing it to the hole 105.When changing the oil, a special jig for opening the built-in valve is attached, and the oil 100 in the oil pan 102 is suctioned at a negative pressure. Then, the jig is removed, the built-in valve is returned to the closed state, and new oil is filled. According to this method, the oil 100 can be forcibly sucked and extracted by the suction device, so that the work can be performed quickly, and apart from the first plug replacement, the plug is removed and re-opened from the next time. This eliminates the need for screwing work, and furthermore provides an excellent advantage that the work can be performed without dirt on the worker and the surroundings with oil.

 However, when the present inventor performed actual work using the above-mentioned conventionally proposed plug with a normally-closed valve, there were some problems such as the inability to mount the plug in some vehicles. It became clear that the possible car types were limited. Therefore, after further study, it was found that these problems are affected by design specifications that differ depending on the vehicle model and subtle misalignment of various mechanisms in the oil pan that do not always require strict mounting position accuracy. .

 That is, in the normally-closed valve built-in type plug disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 8-170782, oil flows in from around the cylindrical portion accommodating the ball valve constituting the normally closed valve. The ball valve and the accommodating part of the panel that normally closes the ball valve are mounted on the oil pan in such a manner as to protrude into the oil pan for a certain length. If there is a structure in the space, the screwing of the plug cannot be sufficient, resulting in poor mounting. Such structures include baffle plates, separators, and strainers for pumping oil that suppress the waviness of oil when the vehicle is running. Although there is no problem, it may not be possible to mount the product due to the misalignment of the mounting position by only a few mm during manufacturing.

In the case of the plug with a built-in normally closed valve disclosed in U.S. Pat. No. 4,745,894, the plug that is mounted on the oil pan in the normally closed state has a mounting end that is approximately the bottom of the oil pan. Since the surfaces are flush, there is no problem that mounting cannot be performed even if a structure exists on the axis of the oil drain hole as described above. When removing oil, the plug of this type moves the valve body located at the end inside the oil pan of the plug in the direction of the oil bun and engages with the valve seat. Since the structure is such that the valve is opened apart from each other, the presence of the above structure results in a problem that the valve cannot be opened even though the plug can be installed. Therefore, in this case, the next oil It becomes clear for the first time that the plug cannot be opened at the time of unthreading work, and the adverse effect in actuality is larger than the above case.

 As described above, the present invention provides a normally-closed valve-integrated plug that has the advantage that the plug is not required to be removed, the operator is hardly contaminated with oil, and the work can be performed quickly. Provides a newly-built normally-closed valve plug that is designed to be universally applicable to all vehicles without being affected by slight misalignment of the internal mechanism mounting position. This was done with the purpose of doing so.

 Another object of the present invention is to provide an oil drain plug that can reduce the length of the oil pan protruding downward from the bottom and reduce the risk of damage to the plug due to so-called rubbing of the bottom of the vehicle. Where you do it.

 Still another object of the present invention is to provide an oil drain plug which has a simple structure, can be easily assembled, is excellent in mass productivity, and is inexpensive. Disclosure of the invention

 The above object is achieved by an oil drain plug according to the present invention having the configuration described in each claim of the present application.

The invention for an oil drain plug for an engine according to claim 1 of the present application is characterized in that a screw shaft portion at one end side on which a male screw formed to be screwed and fixed to an oil drain hole provided in an oil van of an engine device, A bolt head-type head at the other end located outside the oil pan in a fixed state, and penetratingly formed to drain oil from the screw shaft at the one end to the head at the other end. A cylindrical bolt-shaped member having an axial oil drain passage, and an annular valve seat provided near the head in the oil drain passage, and disposed in the oil drain passage of the bolt-shaped member. A valve body for closing the oil drain passage by engaging with the valve seat, and opening the oil drain passage by moving the bracket member from the valve seat toward the inside of the oil pan. Movable valve installed movably in the oil drain passage Member, wherein one end side near the solid in the oil drain passage of said bolt-type member A normally-closed panel member, which is stretched between the fixed portion and the movable valve body member, and urges the movable valve body member with a panel force in a direction of engaging the valve body portion with the valve seat; The movable valve body member is piled and moved by the panel force of the valve normally closed spring member to move the valve body portion away from the valve seat, thereby opening the oil drain passage and draining oil. A plug, wherein a tip of the screw shaft portion is provided so as to be substantially flush with an inner wall surface of the oil pan at the time of the screw fixing.

 In the above-described configuration, it is preferable to employ a configuration in which a liquid-tight seal for strictly preventing leak leakage can be secured on an engagement surface between the valve body portion of the movable valve body member and the valve seat. High durability such as heat resistance and weather resistance, and a seal ring should be interposed. Generally, this seal ring is assembled to a valve body of a movable valve body member.

 In addition, it is preferable to provide a movable guide for the movable valve body member so as to stabilize the movement of the movable valve body member and secure a secure sealing state. For example, the movable valve body member has a cylindrical shape integrated with the valve body portion. It is recommended to adopt a configuration in which a guide portion is provided for guiding the cylindrical portion in the axial direction along the inner wall of the bolt-shaped member.

 Further, in the above configuration, "to make the tip of the screw shaft portion substantially flush with the inner wall surface of the oil pan" does not mean that it is strictly flush, but there is a problem with the conventional method described above. It is only necessary to avoid the problem that the internal structure of the oil pan interferes with plug installation and valve opening. This does not exclude the case where it is provided with a projecting dimension.

According to the present invention, the plug of the present invention having a normally-closed valve incorporates a simple plug used to remove the oil from the oil pan at the time of oil change, and to re-install after oil drainage without particular problem. The valve can be mounted on all types of vehicles without any problems, and the normally closed valve is opened by moving the movable valve element within the plug. It can be secured without being affected by the structure existing in the bread. Therefore, it is possible to solve the problem of the present invention that the conventional type of plug with built-in normally closed valve eliminates the problem that the type of vehicle that can be mounted is limited by the type of vehicle and the like, so that it can always be appropriately applied to all vehicles. . The invention according to claim 2 is the assembly according to the invention, wherein the head of the bolt-shaped member piles and moves the movable valve body member by a panel force and holds the oil drain passage in an open state. It is characterized by having.

 According to the present invention, the circuit of the built-in normally closed valve can be maintained by assembling the jig, so that the burden on the operator is reduced. Can be easily performed.

 The invention according to claim 3 is characterized in that, in each of the above inventions, the annular valve seat provided near the head in the oil drain passage of the bolt-type member is a valve seat forming member separate from the bolt-type member. It is characterized in that the bolt-type member is formed by being fixed with a force crimp at the end.

 According to the present invention, the valve seat, which is an important member for reliably preventing oil leakage when the built-in normally closed valve is closed, is designed so that its material and shape are independent and separate from the bolt type member. There is an advantage that it can be formed by members.

 In the invention according to claim 4, in each of the above-described inventions, the bolt-type member is a panel member accommodating portion for normally closing the valve of the movable valve body member, from one end to the other end inside the oil pan, and the movable valve. The housing portion of the body member and the fixing portion of the valve seat forming member are provided so as to gradually increase in diameter.

 According to the present invention, a panel for normally closing the built-in valve, a movable valve body member, and a valve seat forming member are provided in the oil drain passage of the bolt type member in this order, and the other end side end of the bolt type member is valved. Since the plug of the present invention can be manufactured by squeezing so as to fix the seat forming member, the operation of manufacturing the oil drain plug can be extremely simplified, and an inexpensive product excellent in productivity can be provided. Benefits are obtained. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a longitudinal sectional view showing a state in which the oil drain plug of the first embodiment of the present invention is mounted in an oil drain hole of an oil pan, and a dedicated oil drain jig is assembled to drain the oil.

FIGS. 2A and 2B are views for explaining the oil drain plug of the first embodiment. FIG. 2A is a longitudinal sectional view, FIG. 2B is a perspective view of the movable valve body member, and FIG. Formation It is a perspective view of a member.

 FIG. 3 is a longitudinal sectional view showing a dedicated jig for opening the built-in normally closed valve of the oil draining plug of the first embodiment.

 FIG. 4 is a longitudinal sectional view showing a cap used to protect the oil drain plug of the first embodiment at a normal time other than when oil is changed.

 FIG. 5 is a diagram showing an example of a conventional method for extracting oil from an oil pan of an engine to which the plug of the present invention is applied.

 (Explanation of code)

 1-• Oil drain plug

 2 · •, oil

 3 • • Packing

 4 · · · Protective cap

 5 · · · Sealing

 6-• · Sealing

 7 · · · Dedicated jig for oil removal

 7 1

 71 1

 7 1 2

 7 13

 714

 714 1

 7 142tapered surface

 7143

 71 5Coil spring

 7 16

 717

 7 18

7 1 9 7 2 • · Coupler connection

 · · Hose

 · · Coupler

 1 1 · • Bolt type member

 1 1 1 -Screw shaft

 1 1 1-• Male thread

 1 1 2

 1 1 2 1 • shoulder

 1 2 2.

 1 2 3 • Guideway

 1 1 2 4 • Hexagon bolt head

1 1 3

 1 1 3 1 • (Spring) Seat 1 1 3 2 • • Cylindrical inner wall 1 1 3 3 • Taper

 1 1 3 4 • Large-diameter cylindrical surface 1 1 3 5.

 1 1 3 6 • Taper

 1 1 3 7

 1 2

 1 2 .. Valve seat

 1 2 • · Tapered outer surface

 1 2.

 1 2 •

 1 3Movable valve element

 1 3.

 1 3 1 1

1 3 2 1 3 2 1 · · · Grooves BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the present invention will be described in more detail based on embodiments shown in the drawings.

Embodiment 1

 This example is shown by Fig. 1 to Fig. 4, and Fig. 1 shows a state in which the oil drain plug of this example is attached to an oil pan, and a special oil draining jig is assembled to drain the oil. 2 is a diagram for explaining the oil drain plug of the present example, and FIG. 3 shows a dedicated jig for opening the normally closed valve of the oil drain plug of the present example. Fig. 4 shows the cap used to protect the oil drain plug at times other than oil change.

 In FIG. 1, reference numeral 102 denotes an oil pan, and reference numeral 105 denotes an oil drain hole (female screw hole) provided at the bottom of the oil pan 102. These are the same as those in FIG. The oil drain hole 105 is normally closed by a simple closing plug (see reference numeral 106 in FIG. 5) which does not have a normally closed valve. In the case of using a plug, the above-mentioned closing plug 106 is removed, and a plug 1 for oil drain described below is screwed in and fixed. Reference numeral 2 denotes oil stored in the oil pan 102.

Details of the oil drain plug 1 of this embodiment are shown in FIGS. The plug removing plug 1 of the present example has a screw shaft portion 111 on one end side on which a male screw 111 is formed, and a large portion on the other end side continuous with the screw shaft portion 111. It has a head 1 1 2 provided on the diameter, and a through hole 1 1 3 with a step (from the screw shaft 1 1 1 to the head 1 1 2) with a step (the bolt head has a large diameter step). The valve seat forming member 12 fixed to the vicinity of the opening on the side of the head 1 12 in the through hole 1 13 and the valve seat forming member 12 A movable valve body member 13 housed in the through hole 113 so as to form an on-off valve in cooperation with the formed valve seat 123, and the movable valve body member 133 is connected to the valve seat 131. And a coil spring 14 for urging the spring in the direction of 2 1. The through hole 113 forms an oil drain passage. Explaining each of the above-mentioned members constituting the oil drain plug, as shown in FIG. 2 (a), the bolt-shaped member 11 has the above-mentioned screw shaft portion 11 1 and head portion 11 2. The through hole 1 13 formed through the shaft in the axial direction has the following from the one end of the screw shaft 1 11 side to the other end of the head 1 12 side. The configuration is formed. That is, a coil spring 14 provided as an inward short flange near the screw shaft 1 1 1 side 1 4 1 4 1 end receiving seat 1 1 3 1, following this spring receiving seat 1 1 3 1 and a bolt type member 1 1 extends substantially to the middle position in the axial direction, forms a housing for the coil spring 14, and has a cylindrical inner wall surface on which the movable valve body member 13 slides and guides the axial movement 1 1 3 2 The large-diameter cylindrical surface 1 1 3 4 extending in the direction of the head 1 1 2 via the tapered portion 1 1 3 3 following the cylindrical inner wall surface 1 1 3 2, the large-diameter cylindrical surface 1 Following 1 3 4, a part of a taper 1 1 3 6 for fixing the valve seat forming member 1 2 provided near the head 1 1 2 via the seal ring assembling step 1 1 3 5 1 1 3 6 Protrusions 113 formed on the head portion 112 for fixing the valve seat forming member are formed sequentially.

 The axial dimensions of the screw shaft portion 111 are set in the oil drain hole (female screw hole) 105 of the oil pan 102, and the shoulder portion 1 1 2 The tip is set to be substantially flush with the bottom surface of the oil pan 102 when screwed and fixed with an intervening hole. The outer periphery of the head 1 1 2 of the plug 1 is fixedly held when an exclusive jig for oil drain described later is mounted, and the protective cap 4 also described below is fixed at normal times. A circumferential groove 1 1 2 2 used for holding is provided, and a guide surface 1 1 2 3 having a circular cross section for assembling the dedicated jig and the protective cap 4 is provided in the circumferential groove 1 1 2 2. A hexagonal bolt head 1 12 4 for inserting a plug screw is provided following the screw shaft 1 1 1 to the shoulder 1 1 2 1 of the head.

Next, the valve seat forming member 12 in the above configuration will be described. The details are shown in FIGS. 2 (a) and 2 (c). That is, it has a cylindrical (ring-shaped) structure that is relatively short in the axial direction, and its outer peripheral shape is located near the end of the head 11 12 side. Then, a tapered outer peripheral surface 122 that matches the tapered portion 111 for fixing the bolt-type member 111 is formed. Subsequently, the seal ring is formed. A sealing ring mounting step 1 2 3 paired with the mounting step 1 1 3 5; and an axially extending outer peripheral surface 1 2 4 fitted to the large-diameter cylindrical surface 1 1 3 4 Is provided. As for the shape of the inner peripheral side, the cylindrical inner peripheral surface 125 located on the end side of the head 112 forms a passage for draining oil, and subsequently, the outer peripheral surface A tapered surface is provided to gradually increase the passage diameter to reach 124. The taper surface gradually increasing the diameter of the passage forms the valve seat 122.

 The valve seat forming member 1 2 has a tapered outer peripheral surface 1 2 2 engaged with a crimp fixing taper portion 1 1 3 6 from the head 1 1 2 side of the bolt type member 1 1. After being assembled as described above, the protrusions 113 for fixing the valve seat forming member are fixed to the bolt-type member 11 by pressing.

 Next, the movable valve body member 13 in the above configuration will be described. This is shown in FIGS. 2 (a) and 2 (b). That is, the movable valve body member 13 of the present example includes a cylindrical portion 131, which forms an oil drain passage formed as an end portion on the screw shaft portion 111 side, and an end portion on the head portion 112 side. The cylindrical portion 131 is provided with an oil flow hole 1311 communicating between the inside and the outside, and is uniformly distributed in the circumferential direction to drain the oil. There are three places with holes of appropriate size. The cylindrical portion 13 1 has an outer diameter dimension that allows the cylindrical portion 13 to slide in the axial direction by the cylindrical inner wall surface 11 32 of the bolt-shaped member 11.

 In addition, in the present embodiment, the valve body 1332 is provided in the shape of an inverted head in a state of FIG. 2A, and a circumferential groove 1321 is formed on the outer peripheral surface of the taper. A seal ring 6 which is formed and which can exert a reliable liquid-tight sealing action when seated on the valve seat 121 is attached to the circumferential groove 1321.

 Assembling of the oil drain plug 1 of the present embodiment having the above-described configuration and attachment and fixing to the oil pan 102 will be described.

First, the protrusion 1 1 3 7 is bolted to the bolt-shaped member 11 in a state where it is not caulked, and the coil spring 14 is first inserted through the large opening on the head side through the through hole 1 1 3 into the cylindrical inner wall surface 1 1 3 2 The movable valve body member 13 with the sealing ring 6 assembled is then fitted to the end of the cylindrical portion 13 1 But coil The coil spring 14 is fitted so as to engage with the end of the spring 14, and the coil spring 14 is held in a compressed state.

 Next, after assembling the seal ring 5 into the step portion 113, which is an assembly portion thereof, the valve seat forming member 12 is formed into a tapered outer peripheral surface 1 2 2 through the tapered portion 1 1 3 of the through hole 1 13. The valve seat forming member 12 is fixed by caulking the projection 113 so as to engage with the projection 13, the holding of the movable valve body member 13 is released, and the assembling operation is completed.

 As described above, the assembly of the oil drainage plug 1 of this example can be performed extremely easily, is excellent in mass productivity, and has a small number of parts, so that the product can be supplied to the market at low cost. Further, since the valve seat forming member 12 can be centered by engaging the tapered portion with the bolt type member 11, positioning can be performed with high accuracy, prevention of oil leakage by the seal ring 5, and movable valve body member Oil leakage can be prevented by the secure engagement of the seal ring 6 of 13 and the valve seat 12 1, and a highly reliable plug free of oil leakage can be provided.

 The plug 1 of this example manufactured in this manner is obtained by removing the existing simple plug 106 (see FIG. 5) assembled in the oil drain hole 105 of the oil pan 102, and then removing the plug. By screwing the screw shaft portion 111 into the oil drain hole 105 with the packing 3 interposed, it can be assembled and fixed to the oil pan 102. At this time, the head of the bolt-shaped member 11 It is used for screw-in work using a screw-in jig such as a hexagonal bolt head provided in the part 112.

 For the plug 1 assembled and fixed as described above, the protection cap 4 shown in Fig. 4 is normally attached to the head 1 1 2 Part. The protective cap 4 of the present example is provided with a bolt-type bolt on a part of the body inner wall 4 2 of the body 4 1 having a circular cross-section to be fitted to the circular guide surface 1 1 2 3 of the bolt-shaped member head 1 2. Although formed as a rubber cap configured to have a circumferential projection 43 fitted into the circumferential groove 1 1 2 2 of the member head 1 2, the end of the bolt-type member head 1 2 The material and structure are not limited as long as they can be securely attached and held to the parts.

Next, as described above, the oil drain plug 1 of this example is assembled and fixed. A preferred operation for draining oil from Lupine 102 will be described.

 This preferable operation is performed using the special jig 7 for oil drain shown in FIG. 3, and the state during the oil drain operation is shown in FIG.

 The special jig 7 for oil removal used in this example is a coupling that turns on and off the fluid flow by attaching and detaching a general socket and a plug, that is, a normally closed valve is installed on one of the socket and the plug. When the socket and plug are detached, the normally-closed valve closes.When the socket and plug are fitted and fitted, the normally-closed valve is opened to allow fluid to flow. Can be configured.

 That is, the exclusive jig 7 for draining the oil used as a socket that forms a coupling with the plug 1 of the present example is covered with the guide surface 1 123 of the head 1 112 of the plug 1. A large-diameter plug fitting portion 71 on one end side having an inner wall surface 71 1 with a circular cross section so that it can be fitted, and a coupler connecting portion 72 on the other end side for connecting an oil suction hose 8. An axial through hole extending from the plug fitting portion 71 to the coupler connecting portion 72 is formed as an oil drain passage 73.

 The plug fitting portion 71 is directed radially outward so as to restrict the protrusion of the ball beyond a predetermined length inward in the radial direction and to allow the ball to move freely outward. A plurality of ball receiving holes 7 1 and 2 provided in the ball receiving hole 7 1 and 2 provided in the ball receiving hole 7 1 and 2 are arranged uniformly in the circumferential direction. Is provided with an attachment / detachment switching mechanism in which an annular cylindrical ball movement restricting slider 7 14 for restricting the movement to two positions is provided. The ball movement restricting slider 714 is pressed to one end side by a coil spring 715 provided on the outer periphery of the plug fitting portion 171 and is prevented from falling off by a locking ring 716. In this case, the ball 7 13 is constrained to a position where the ball 7 13 projects radially inward by the inner peripheral surface 7 14 1 of the slider 7 14. When the slider 7 14 is moved toward the other end side against the panel force of the coil spring 7 15, the ball 7 13 is moved radially outward by the tapered surface 7 14 2 at the tip. To be able to move towards. In addition, the tip protrusion 714 of the slider 711 is a stopper for the ball 713.

In addition, this dedicated jig 7 is attached to the plug 1 at the bottom of the inner cylinder of the plug fitting part 71. The movable valve body member 13 that opens the normally-closed valve with the plug built-in when pressed is provided with a pressing rod 7 17 for movement. The pressing rod 717 is provided so as to extend a predetermined length from the central portion of the bottom portion 718 of the plug fitting portion 71 in which a plurality of oil drain passages are formed in the axial direction toward one end. The extension length is set so that the movable length of the movable valve member 13 when the dedicated jig 7 is attached to the plug 1 is appropriate. Reference numeral 719 denotes a sealing member for preventing oil leakage when the dedicated jig 7 is attached to the plug 1, and is attached to the bottom of the inner cylinder of the plug fitting portion 71, and It is designed to be elastically attached to the end face of the valve seat forming member 12 of the plug.

 One end of a hose is fixed to the coupler 9 fitted to the coupler connecting portion 72, and the other end of the hose 8 is connected to a negative pressure suction device (not shown).

 Fig. 1 shows a state in which the exclusive jig 7 configured as described above for removing oil is assembled and fixed to the oil pan 102 with the protective cap 4 of the plug 1 of this example removed. When the dedicated jig 7 is fitted and assembled, the pressing rod 7 17 presses and moves the movable valve body member 13 of the plug 1 to separate the valve body 13 2 from the valve seat 12 1 and normally closes. The valve is opened, and the seal member 7 19 engages with the end face of the valve seat forming member 12 to perform a liquid-tight seal. Therefore, the oil in the oil pan 102 can be forcibly sucked and extracted by the negative pressure action from the negative pressure suction device (not shown) through the hose 8.

 At this time, since there is nothing protruding into the oil pan 102 from one end of the plug 1, the normally closed valve should be opened and closed smoothly without any restrictions on the mechanism and structure in the oil pan. Can be. Industrial applicability

 As described above, according to the present invention, a plug with a built-in normally-closed valve that has the advantage that the plug does not need to be removed, the operator is hardly contaminated with oil, and the work can be performed quickly, The effect that, for the first time, it is possible to realize universal application to all vehicles with the plug with built-in normally closed valve of the same standard without being affected by slight displacement of the mounting position of the mechanism inside the oil pan Is obtained.

Further, the oil drain plug of the present invention is a movable valve suitable for opening the normally closed valve. Since the screw shaft part can be used as the accommodation part for the panel for pressing the valve body, the total length of the plug can be shortened compared to the above-mentioned conventional type, because the dimensions required to secure the moving length of the body member can be used. For example, by reducing the length of the oil pan that protrudes downward from the bottom, the effect of reducing the possibility that the so-called rubbing of the bottom of the vehicle damages the plug can be reduced.

 Further, the oil drain plug of the present invention has a simple structure, can be easily assembled, and is excellent in mass productivity, so that the oil drain plug can be provided at a low cost. You.

 Furthermore, in the type in which the oil drain plug of the present invention is mounted on the bottom surface of the oil pan, the inner end of the oil pan can be mounted flush with the bottom surface of the oil pan. An effect that an extremely small amount of L and a state can be secured is also exerted.

Claims

The scope of the claims (Claim 1) A screw shaft portion at one end side on which a male screw formed to be screwed and fixed to an oil drain hole provided in an oil pan of an engine device, and an outer portion of the oil pan when the screw is fixed. A bolt-type head on the other end side, and an axial oil drain passage formed to penetrate oil from the screw shaft portion on the one end side to the head on the other end side; A cylindrical bolt-shaped member having an annular valve seat provided near the head in the oil drain passage;  A valve body that is disposed in the oil vent passage of the bolt-type member and that closes the oil vent passage by engaging with the valve seat; A movable valve body member movably mounted in the oil drain passage so as to open the oil drain passage by moving;  The movable valve body member is mounted on the movable valve body member in a direction in which the valve body portion is engaged with the valve seat by being stretched between the fixed portion and the movable valve body member in the oil drain passage of the bolt type member. A panel member for normally closing the valve that biases the force, The movable valve body member is piled up and moved by the spring force of the valve normally-closed spring member to move the valve body portion away from the valve seat, thereby opening the oil drain passage and draining the oil. It is a plug for oil removal,  An oil drain plug for an engine, wherein a tip of the screw shaft portion is provided so as to be substantially flush with an inner wall surface of the oil pan when the screw shaft is fixed. (Claim 2) The assembly according to claim 1, wherein the head of the bolt-type member is mounted with a jig for moving the movable valve body member against the panel force and holding the oil drain passage in an open state. A plug for draining oil from an engine, characterized by having a portion.  (Claim 3) In Claim 1 or 2, the annular valve seat provided near the head in the oil drain passage of the bolt-type member comprises a valve seat forming member separate from the bolt-type member. A plug for removing a hole in an engine, wherein the plug is formed by fixing with a force crimp at an end of a bolt-type member. (Claim 4) In any one of claims 1 to 3, the bolt-type member may be an oil From one end inside the pan to the other end, the panel member housing for the normally closed valve of the movable valve member, the housing for the movable valve member, and the fixed portion of the valve seat forming member gradually increase in diameter. A plug for draining oil from an engine, wherein the plug is provided so as to be disposed as follows.