JPH0218256Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an attachment structure for a timing gear cover that covers a timing gear train disposed on one side of an engine body.

The timing gear cover needs to cover the entire surface of the timing gear train including the crankshaft gear, idle gear, camshaft gear, etc., so it is formed over a wide area. Since severe vibrations caused by combustion pressure fluctuations, torque fluctuations, etc. are transmitted to the timing gear cover from the engine body, membrane vibration is likely to occur, which is one of the causes of engine noise.

Therefore, in order to suppress the membrane vibration, attempts have been made to increase the wall rigidity by forming the cover into a curved shape or adding reinforcing ribs, but these efforts not only do not have a sufficient effect of suppressing membrane vibration, but also increase the weight. , leading to inconveniences such as an increase in space.

As a solution to this problem, the
There is a prior art disclosed in Publication No. -90725. This prior art focuses on the fact that the part that covers the idle gear is located in the center of the timing gear cover, where the amplitude of membrane vibration is the largest, and fixes this part to the end face of the idle gear support shaft using bolts. This significantly reduces membrane vibration.

The present invention makes use of the engine noise reduction effect of the prior art, improves the mounting structure of the timing gear cover to the idle gear support shaft, and lubricates the timing gear train by operating the screw shaft such as the bolt. The oil amount can be adjusted to an appropriate value to ensure reliable and appropriate lubrication of the timing gear train, thereby improving its reliability.

The present invention, as illustrated in the illustrated embodiment,
An internal lubricating oil passage 4 is formed in the idle gear support shaft 1, and an end of the internal lubricating oil passage 4 on the side of the engine body 8 communicates with a lubricating oil supply passage 20 in the engine body 8, and the other end is connected to the lubricating oil supply passage 20 inside the engine body 8. The idle gear support shaft 1 is connected to a supply pipe 26 and configured so that the lubricating oil supplied from the lubricating oil supply passage 20 to the internal lubricating oil passage 4 is spouted toward the gear meshing part through the oil supply pipe 26. The tip needle part 27 of the screw shaft 3 with a needle screwed into it from the end surface 2 is disposed in the oil amount adjustment part of the internal lubricating oil passage 4, and depending on the axial position of the screw shaft 3 with a needle, the internal lubricating oil passage A soft elastic member is provided between the head 5a of the needle screw shaft 3 or the nut 5b screwed thereto and the end surface 2 of the idle gear support shaft 1. 6 is interposed therebetween, and a substantially central portion of the timing gear cover 7 is held under pressure between the soft elastic member 6 and the end surface 2 of the idle gear support shaft 1.

The present invention will be explained in detail below based on embodiments shown in the drawings.

The embodiment shown in FIGS. 1 and 2 relates to a mounting structure for a timing gear cover 7 of a diesel engine.

A timing gear train consisting of a crankshaft gear 9, an idle gear 10, a camshaft gear 11, and a fuel injection pump drive shaft gear 12 is disposed on one side of the engine body 8.
The area around the timing gear train is constructed using a case fixed to the engine body 8 (not shown as it is located on the back side of the timing gear train) and a large number of bolts 13, 13, etc. to this case. It is covered with a timing gear cover 7 to which the timing gear is fixed.

As shown in FIG. 2, the idle gear support shaft 1 that supports the idle gear 10 is formed in the shape of a stud, and is screwed and fixed into a screw hole 14 formed on one side of the engine body 8. There is. Further, a stepped collar 15 is fitted around the outer circumference of the idle gear support shaft 1 to fix the idle gear support shaft 1 to the engine body 8, and at the same time, the stepped collar 15 is fitted between the idle gear support shaft 1 and the engine body 8. It is clamped and fixed in between. An idle gear 10 is rotatably supported in the small diameter portion of the stepped collar 15, and movement of the idle gear 10 in the axial direction is restrained by the stepped portion 16 of the stepped collar 15.

A stepped hole having a large diameter on the end surface side and a small diameter on the shaft side is provided in the axial center of the idle gear support shaft 1 in a penetrating state, and a screw is inserted into the large diameter hole 17 of the stepped hole toward the inside from the end surface 2. 18, into which the threaded shaft 3 with a needle is screwed. Small diameter hole portion 19 of the stepped hole
communicates with a lubricating oil supply passage 20 in the engine body 8 via a screw hole 14 in the engine body 8 .

From the lubricating oil supply passage 20 to the small diameter hole 19
A part of the lubricating oil supplied to the needle screw shaft 3
and passages 2 provided in the radial direction of the stepped collar 15
1 and 22, the oil reaches the oil groove 23 on the outer periphery of the stepped collar 15, and lubricates the inner peripheral surface of the hole of the idle gear 10. On the other hand, the remainder of the lubricating oil enters the large diameter hole 17 from the small diameter hole 19, passes through passages 24 and 25 provided in the radial direction of the needle screw shaft 3 and the stepped collar 15, and then enters the oil supply pipe. 26, and is ejected from its tip toward the meshing portion (gear meshing portion) between the idle gear 10 and the camshaft gear 11.

The screw shaft 3 with a needle is composed of a bolt having a needle portion 27 at the tip of the shaft portion.
The tip reaches inside the oil amount adjusting portion, that is, the tip of the small diameter hole portion 19, and forms a needle jet 28. Then, by rotating the screw shaft 3 with a needle to change the axial position, the small diameter hole 1
9. The lubricating oil flow rate of the internal lubricating oil passage 4 consisting of the large diameter hole 17 and the radial passage 24 can be adjusted, and the meshing parts between the idle gear 10 and other gears can be reliably and properly lubricated. . Note that 29 is a seal ring that seals between the idle gear support shaft 1 and the stepped collar 15 to prevent lubricating oil from leaking to the outside.

At approximately the center of the timing gear cover 7, a mounting hole 29 is provided through which the needle screw shaft 3 and the soft elastic member 6 described below are inserted. As shown in FIG. 2, a bush-shaped soft elastic member 6 made of a soft elastic material such as rubber is fitted into the mounting hole 29, and a screw shaft with a needle is inserted through the soft elastic member 6. 3 into the screw 18 of the large diameter hole 17 of the idle gear support shaft 1, the head 5a of the screw shaft 3 with needle
A soft elastic member 6 is interposed between the end face 2 of the idle gear support shaft 1 and a substantially central portion of the timing gear cover 7 is sandwiched between the soft elastic member 6 and the end face 2 of the idle gear support shaft 1. keeping. Due to its elasticity, the soft elastic member 6 has the function of preventing the needle screw shaft 3 from loosening even if the axial position is arbitrarily selected, and also absorbs vibration while moving the needle screw shaft 3 approximately at the center of the timing gear cover 7. It has the function of pressing and fixing the part against the end face 2 of the idle gear support shaft 1. Furthermore, the soft elastic member 6 also functions as a sealing material to prevent lubricating oil from leaking to the outside. Note that 30 is a metal cap integrally attached to the top surface of the soft elastic member 6.

The present invention can be configured in various ways other than those shown in the above embodiments. For example, in the embodiment shown in FIG. 3, a headless screw shaft having a driver engagement groove 31 is used as the needle screw shaft 3, and the axial position can be adjusted by rotating the screwdriver. At the same time, the substantially central portion of the timing gear cover 7 is fixed by tightening a nut 5b screwed onto a screw on the outer periphery. Further, in this embodiment, the idle gear 10 is rotatably supported directly on the idle gear support shaft 1.

Further, in both of the above embodiments, the idle gear support shaft 1 is fixed by screwing into the screw hole 14 of the engine body 8, but the idle gear support shaft 1 may be fixed to the engine body 8 using a separate mounting bolt. You can also do it. Furthermore, it is also possible to apply the present invention to a mounting structure for a timing gear cover of a gasoline engine.

Since the present invention has the above-mentioned configuration, a soft elastic member is interposed between the head of the needle screw shaft or the nut screwed thereto, and the end face of the idle gear support shaft, so that the approximately central portion of the timing gear cover is It can be held under pressure between the elastic member and the end face of the idle gear support shaft, thereby significantly reducing membrane vibration of the timing gear cover and reducing engine noise.

Further, according to the present invention, the flow rate of lubricating oil in the internal lubricating oil passage can be adjusted by using the screw shaft with the needle, so that the complexity of the structure can be minimized, and the timing gear The train can be reliably and appropriately lubricated, and the reliability of the timing gear train can be improved.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of the present invention, Fig. 2 is an enlarged longitudinal sectional plan view taken along the - line in Fig. 1, and Fig. 3 is an enlarged longitudinal sectional plan view of main parts showing another embodiment of the invention. It is. 1... Idle gear support shaft, 2... End face, 3... Screw shaft with needle, 4... Internal lubricating oil passage, 5a... Head,
5b... Nut, 6... Soft elastic member, 7... Timing gear cover, 8... Engine body, 20... Lubricating oil supply passage, 26... Oil supply pipe, 27... Needle part.

Claims (1)

[Scope of utility model registration request] An internal lubricating oil passage is formed in the idle gear support shaft, an end of the internal lubricating oil passage on the side of the engine body is communicated with a lubricating oil supply passage in the engine body, and the other end is connected to an oil supply pipe, The lubricating oil supplied from the lubricating oil supply passage to this internal lubricating oil passage is configured to be ejected toward the gear meshing portion through the oil supply pipe, and the needle screw shaft is screwed into the idle gear support shaft from the end face thereof. The tip needle portion is disposed in the oil amount adjusting portion of the internal lubricating oil passage, and the lubricating oil flow rate of the internal lubricating oil passage can be adjusted by the axial position of the screw shaft with the needle. A soft elastic member is interposed between the head of the threaded shaft or a nut screwed thereon and the end face of the idle gear support shaft, and a timing gear cover is provided between the soft elastic member and the end face of the idle gear support shaft. A mounting structure for an engine timing gear cover, characterized in that a substantially central portion of the engine is held under pressure.