JPS60101208A - Sealed type hydraulic rush adjuster - Google Patents

Abstract

PURPOSE:To make sure of installation, by letting each end of a diaphragm pass through plural holes of a retainer, and coupling these projecting parts altogether, in case of a rush adjuster which presses the lower end of the diaphragm forming a reservoir chamber to a plunger body by means of the retainer. CONSTITUTION:A plunger 43 is slidably inserted into a plunger body 41, and a high pressure chamber 42 is partitioned by a check valve 51, while a reservoir chamber 57 is formed on the circumference of a projecting part of the plunger 43 by a diaphragm 55. A lower end of the diaphragm 55 is forcibly pressed to the plunger body 41 by a retainer 45. In this retainer 45, a ring plate 60 regulating an upper motion limit position of the plunger 43 is provided with plural holes into which each lower end of the diaphragm 55 is passed through and made to jut out into the inside of the retainer whereby these projecting parts are coupled together with one another. With this constitution, the diaphragm is firmly locked to the retainer over a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lash adjuster used in a valve mechanism of a four-stroke engine, and more particularly to a sealed hydraulic lash adjuster (hereinafter simply referred to as the lash adjuster) that utilizes hydraulic pressure. It is something that

Lash adjusters aim to achieve quiet operation and maintenance-free operation by using the elastic force of the elastic member and hydraulic pressure to operate the valve train with zero lash, and are used in various 4-stroke engines. It's starting to get worse.

1 and 2 show a lash adjuster provided as Japanese Patent Application Laid-open No. 51-142179, and this lash adjuster 1 is used to open and close a valve 2 of a four-stroke engine. We support
A valve train cam 4 is disposed above the rocker arm 3, and the J valve train is operated with zero lash.

The lash adjuster 1 includes a plunger 8 that forms a high pressure chamber 7 between the plunger body 6 and the plunger body 6, shown in FIG. The plunger 8 is urged upward by the resilient member 9, and an annular groove 68 is formed at the upper end of the inner peripheral part of the plunger body 6, and the snap ring 10 fitted in the groove 6a prevents the plunger 8 from coming off downward. This is what I tried to prevent.

The plunge V7B has a hemispherical head that supports one end of the rocker arm 3 at its upper end, and
A reservoir chamber 11 is formed inside the plunger 8. This reservoir chamber 11 has a communication passage 1 passing through the bottom of the plunger 8.
The high pressure chamber side opening of the communication passage 12 is provided with a reverse valve 13 that allows only the flow of hydraulic oil from the reservoir chamber 11 to the high Tf chamber 7. .

Further, the plunger 8 is formed with communication passages 14 and 15 for communicating the reservoir chamber 11 with the outside, and one of the two reverse passages 14 and 15 is connected to the LSI.
A check ball 17 urged upward by the resilient member 16 is interposed, and a check ball 19 urged downward by the resilient member 18 is interposed in the other communicating path 15. The pressure within the reservoir chamber 11 is always maintained within a predetermined range.

Further, on the upper outer periphery of the plunger body 6, one side edge of a substantially cylindrical diaphragm 20 made of a flexible material is pressed against its outer periphery by caulking of an annular metal retainer 21, so that the plunger body 6 is fluid-tightly inserted into the plunger body 6. The diaphragm 20 is fixed to the upper outer periphery of the body 6, and the other edge of the diaphragm 20 is fixed to the upper outer periphery of the plunger 8 in a fluid-tight manner. Thus, the space 22 formed between the inner surface of the diaphragm 20 and the n section of the plunger 8 is sealed.

Note that 23 communicates between the space 22 and the arbor 11.
There is a communication path C.

The lash adjuster 1 configured in this manner is configured so that when a gap (lash) is generated between the rocker arm 3 of the valve train and the valve cam 4, the 'r'('valve part (
The plunger 8, which is forced upward (A9 to J), moves upward U1 and absorbs this gap. Further, with the upward movement of the plunger p8, the hydraulic oil in the reservoir chamber 11 flows into the high pressure chamber 7 through the communication passage 12, and at this point, the operating force of the valve operating cam 4, etc. Even if compressive force is applied to the check valve 13, the hydraulic oil flowing into the high pressure chamber 7
Since the flow in the opposite direction is diverted by
It's hot. However, in response to an impact force such as when the cam starts up, a part of the hydraulic oil in the high pressure chamber 7 flows into the space 22 through the clearance between the sliding surfaces of the plunger body 6 and the plunger v8. Furthermore, it is returned into the reservoir chamber 11 via the communication path 23, which reduces the impact and enables quiet operation.

By the way, - in the above-mentioned lash adjuster (, l
, the lower end of the tie A7 flamm 20 is pressed inward by the caulking of the retainer 21, and is fixed only by the frictional force generated between the retainer 21 and the plunger body 6. The fixing force of the diaphragm 20 is weak, and as the diaphragm 20 repeatedly expands and contracts, the lower end of the daisephram 20 shifts upward, causing the diaphragm 2
There was a risk that the liquid tightness between the plunger body 6 and the plunger body 6 would be impaired.

If the liquid tightness is compromised, oil may leak or air may enter from there, and the plunger 8 will no longer be held rigidly, resulting in a lack of air pressure and, in turn, a drop in engine output. .

The present invention was made in view of the above circumstances, and by making the retainer at the lower end of the diaphragm integral (14 structures),
A sealed hydraulic system that can firmly and liquid-tightly fix the lower end of the diaphragm to the retainer for a long period of time, and maintain good liquid tightness between the lower end of the diaphragm and the upper outer circumference of the plunger body for a long period of time. The purpose is to provide a lash adjuster.

An embodiment of the present invention will be described below with reference to the drawings. Third
The figure shows a lash adjuster according to the present invention, and in the figure, reference numeral 41 is a cylindrical plunger body at the bottom right, inside which is a plunger /I3 that forms a high pressure chamber 42 between the plunger body /11. '' is slidably inserted with the second part protruding. Plunge 1743
is urged upward by the resilient member 4/1, and is prevented from falling off upward by a retainer /I5, which will be described later.

J lange +7/13 has large diameter portions/16, 47 which are slidably fitted to the inner peripheral surface of the plunger body 41 at the lower part and the center portion in the length direction, and these two hole diameter portions 46
．． It has a structure in which an annular @48 is formed between /17. 31, the upper end of the plunger 43 is formed into a hemispherical shape so that it can rotatably abut against the lower end of the rocker arm. An annular space 49 is formed between the annular groove 48 and the inner peripheral surface of the plunger body/11, and this space 49 is communicated with the high pressure chamber 42 via a communication passage 50 formed in the plunger 43. There is. A check valve 51 is provided at the opening of the communication passage 50 on the high pressure chamber 42 side, 45L, which allows only the flow of hydraulic oil from the communication passage 50 to the high pressure chamber 42 side.

Is the check valve 51 at the height 1+? A ball cage 52 is attached to the snap ring 5 on the bottom of the plunger +743 which defines ./12.
3 and has a structure in which a check ball 54 is housed in a ball cooler 52.

On the other hand, a diaphragm 55 formed in a substantially cylindrical shape is liquid-tightly fixed to the outer periphery of the head of the plunger/I3 by caulking a retainer 5G, and the lower end of the diaphragm 55 is attached to the upper outer periphery of the body 41 of the plunger 17. /I5
It is fixed in a liquid-tight manner. Then, J, re-diaphragm; -i5 inner peripheral surface and plunger tr/
A reservoir chamber 57 is defined between the shield parts of 13, and this reservoir chamber 57 is connected to the space 49 through a communication passage 58.50.
J> J: and communicates with the high pressure chamber 42.

Plunger body 41 at the lower end of the dye hair 7 flamm 55
4 and 5, the tape 45 is fixed to a ring plate 60 having a plurality of holes 59 provided at intervals in the circumferential direction. A cylindrical portion 6 extending downward from the outer peripheral edge of the plate 60
The lower end of the cylindrical portion 61 is directly caulked and fixed to an annular groove 62 formed on the outer periphery of the small diameter portion of the plunger body 41. The lower end of the diaphragm 5 passes through the hole 59 of the ring plate 60 of the retainer 45 and protrudes downward from the ring plate 60, and the protruding portions 55a are connected to each other. The target is pressed against the upper outer periphery of the plunger body/'11.

Nayoe 1-Note (In addition to the 111 formation, if the lower end of the die A7 flamm 55 and the retainer/I5 are covered so as to be bonded via adhesive, the lower end of the die A7 flamm 55 and the retainer 45 can be made stronger. It can be combined. Also, Fig. 3 i]
63 is a plug that closes the upper part of the communication path 50.

Therefore, the lash adjustment configured as described above (j, between the rocker arm of the valve train and the valve train cam <K
If there is a gap between the
: Plunge +743, which is urged upward, moves upward and absorbs this gap. Further, as the plunger 1143 moves, the hydraulic oil in the reliever 7-57 flows into the communication passage 58.
．． 50 into the high pressure chamber 42, at this time jj,
Even if compressive force is applied to the pusher 1 adjuster due to the operating force of the valve drive cam, etc., the hydraulic oil flowing into the high pressure chamber 42 is stopped from flowing in the opposite direction by the valve 51. , the entire lash adjuster remains properly rigid and transmits the operating force of the valve operating cam to the valve via the rocker arm.

Furthermore, when the plunger 1/43 moves up and down with respect to the plunger body 41, the volume of the high pressure chamber 42 changes;
The amount of change in A is due to the diameter expansion and diameter reduction of the die-filled 7-flamm 55.
It is absorbed by the volume change of the reservoir seedling 57.

Moreover, according to the Lassi core adjuster having the above-mentioned bow configuration, a plurality of holes 59 are formed in the ring plate 60 of the retainer 45, and the lower end of the diaphragm 55 is passed through the wire hole 59 to protrude U.
By connecting these protruding portions 55a to each other, the lower end of the diaphragm 55 and the retainer 45 are integrated.
5 can be strongly combined. Also, retainer 4
The lower end protruding portion 55a of the diaphragm that protrudes into the inside of the plunger body 55 is pressed against the upper outer periphery of the plunger body 41 in a state where they are not connected to each other, and the lower end portion 55a of the diaphragm is liquid-tightly sealed between the retainer 45 and the plunger body/11. Because it is used as a sealing member, it also has the advantage of reducing the number of parts.

In addition, according to the above embodiment, the retainer 45
7 The lower end of the flamm 55 is pressed against the plunger body 41 14
48 nIA and the function of regulating the upper limit neck of the plunger 7I3, there is no need to install the snap ring 10 shown in the conventional example in FIG. 2. Also, of course, there is no need to provide a groove in the plunger body 41 for fitting the snap spring 10. Therefore, the length of the plunger body 41 can be made shorter than the conventional one shown in FIG. The entire adjuster can be shortened.

Furthermore, if J is applied to the above embodiment, the length of the 1:41 moving portion between the plunger body 41 and the plunger 43, which is related to leakage from the high pressure chamber 42 to the reservoir chamber 57, is the length of the annular groove 48.
The lower part of the IJ is shorter than the conventional one shown in FIG. 2, which does not have an annular groove in the middle. Therefore, even if the clearance of the sliding part is small, the desired amount of leakage can be obtained without reducing the resistance to leakage. and improved durability.

Furthermore, in the above embodiment, since no sealing member is interposed inside the lower end of the retainer 45, the retainer 45
Make sure to caulk the bottom edge! I can. Furthermore, the second
The lash adjuster shown in the figure has a sealing member made of an elastic material interposed inside the retainer 21, and has the disadvantage that it cannot be crimped strongly.

In addition, in the above embodiment a3, a hole 59 is provided in the ring plate 60 of the retainer 45, and the diaphragm 55 is inserted into this hole 59.
Although the lower end is penetrated, the cylindrical portion 61 may be provided with a hole and the lower end of the die A7 flammable 55 may be penetrated through this hole.

As explained above, according to the present invention, the lower end of the diaphragm is made to protrude into the retainer by penetrating the plurality of holes formed in the retainer, and by making these protruding portions stick to each other, the lower end of the diaphragm is Since the retainer and the retainer are constructed as an integral structure, the lower end of the diaphragm can be firmly and liquid-tightly fixed to the retainer. J. The protruding lower end of the diaphragm that protrudes into the retainer is pressed against the upper outer periphery of the plunger body and is used as a seal between the retainer and the plunger body, which reduces the number of parts. , it is possible to seal the space between the retainer and the plunger body to IQ f, and as a result, it is possible to maintain a good liquid tightness 1 (1) between the lower end of the diaphragm and the upper outer periphery of the plunger body for a long period of time. It will be done.

[Brief explanation of the drawing]

1 and 2 show a conventional example of a lash adjuster, FIG. 1 is a schematic diagram of the entire valve train system, FIG. 2 is a vertical cross-sectional view of the lash adjuster, and FIG. 3 is an embodiment of the present invention. A vertical cross-sectional view showing an example, Figure 4 is an enlarged view of the inside of IV in Figure 3, Figure 5 is an enlarged view of the inside of IV in Figure 3,
The figure is a perspective view of the retainer. 1... Lash adjuster, 2... Valve, 3... Rocker arm, 4... Valve cam, 41... Plunger body, 42...
... Hyperbaric chamber, 43 ... Plunger, 47I.
...Bulging member, 45...Retainer, 71
8... Annular groove, 49... Space, 51.
...Check valve, 55...Diaphragm, b
5a...Protruding portion, 57...Reservoir chamber, 60...Ring plate. Applicant: Honda Motor Co., Ltd. Nigyo Co., Ltd. 1 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] The plunger body has a cylindrical shape with a bottom, and the upper part of the plunger body can be slid freely within the plunger body. This is a sealed hydraulic lash adjuster that includes an inserted plunger, a high pressure chamber formed between the lower surface of the plunger and the bottom surface of the plunger body, and a reservoir chamber that communicates with the high pressure chamber via a check valve. Then, the protrusion 8 of the plunger
1) An end of a substantially cylindrical diaphragm defining the reservoir chamber inside is liquid-tightly fixed to the upper outer periphery, and a lower end of the diaphragm is liquid-tightly fixed to the upper outer periphery of the plunger body via a retainer. The lower end of the diaphragm is fixed to the outer periphery of the upper part of the plunger body 41 such that the lower end of the diaphragm protrudes into the retainer through a plurality of holes formed in the retainer, and these protruding portions are connected to each other. A sealed hydraulic lash adjuster, characterized in that it has a structure in which it is pressure-welded to the upper outer periphery of the plunger body.