JPS60101207A - Sealed type hydraulic rush adjuster - Google Patents

Abstract

PURPOSE:To form a device into such a structure that dispenses with special parts that prevent a plunger from slipping off, by installing a ring for regulating an upper motion limit position of the plunger, in a retainer which presses a diaphragm to a plunger body under pressure. CONSTITUTION:A plunger 43 is slidably fitted in a plunger body 41, and a high pressure chamber 42 is partitioned by a check valve 51, and that a reservoir chamber 57 is formed on the circumference of a projecting part of the plunger 43 by means of a diaphragm 55. A lower end of the diaphragm 55 is forcibly pressed to the plunger body 41 by a retainer 45. On the other hand, this retainer 45 is provided with a ring plate 60 through which an upper motion limit position of the plunger 43 is regulated, with this constitution, the plunger 43 is preventable from slipping off without installing any special parts for this purpose.

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 a lash adjuster) that utilizes hydraulic pressure.

Lash adjusters are designed to achieve quiet operation and maintenance-free operation by using the elastic force of an elastic member and hydraulic pressure to cause the valve train to operate in a lashing manner, and are used in various 4-cycle engines. It's starting to get worse.

1 and 2 show a lash adjuster provided as Japanese Patent Application Laid-Open No. 54-14.2179.

This lash adjuster 1 supports one end of a rocker arm 3 that opens and closes a valve 2 of a four-stroke engine.
The valve train is operated with zero lash.

? In other words, 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 this groove 68 is pushed upwardly by the plunger v8. This is to prevent the use of

The plunger 8 has a hemispherical head at its upper end that supports one end of the rocker arm 3, and has a reservoir chamber 11 formed therein. This reservoir chamber 11 is communicated with the high pressure chamber 7 via a communication passage 12 passing through the bottom of the plunger 8, and the opening of the communication passage '12 on the high pressure chamber side allows the flow of hydraulic oil from the reservoir chamber 11 to the high pressure chamber 7. A check valve 18 is provided which allows only the

Furthermore, communication passages 14 and 15 for communicating the reservoir chamber 11 to the outside are formed in the plunger 8, respectively.
A check ball 1 urged in the −L direction by an elastic member 16 is provided in one of the communication paths 14 of these two-speed paths 1115.
7 is interposed, and the other communication path 15 is provided with an elastic member 18.
A check ball 19 that is urged downward is interposed, so that 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 inward direction of the diaphragm 20 and the shoulder of the plunger 8 is sealed.

Note that 23 is a communication path that communicates the space 22 and the reservoir chamber 11.

This j, the lash adjuster 1 that was made is
When a gap (lash) is about to occur between the rocker arm 3 of the valve train and the valve train cam 4, the resilient member 9
ni J: ``downward'' (plancito 8, which is being pushed q,
1-Movement 1) absorbs this gap. Also plunger 8
Due to the upward movement of the hydraulic fluid in the reservoir chamber 11,
The valve cam 4 flows into the high pressure chamber 7 through the
Even if a compressive force is applied to the lash adjuster 1 due to the operating force of
If the flow in the opposite direction is +t,
The entire lash adjuster 1 remains rigid with an appropriate length, and transfers the operating force of the valve cam 4 to the valve 2 via the rocker arm 8.
to communicate. 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 8, and further 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 -'r-A lash adjuster, in order to prevent the plunger 8 from falling off, an annular groove 68 is provided in the upper inner peripheral surface of the plunger body 6, and a snap ring 10 is attached to this groove 6a. Because of this configuration, a snap ring 10 is required to prevent the plunger 8 from falling off, and an annular groove 68 is provided on the inner peripheral surface of the plunger body 6.
needed to be formed. In addition, the above-mentioned lash adjuster had drawbacks such as the formation of the annular groove 68 (the knob plunger body 6 had to be lengthened, making the overall lash adjuster relatively better).

The present invention has been made in view of the above circumstances, and does not require special parts such as a snap ring to prevent the plunger 1B2 from falling, and does not require the formation of an annular groove on the inner circumference of the plunger body. It is another object of the present invention to provide a sealed hydraulic lash adjuster whose overall length can be further shortened.

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 denotes a cylindrical plunger body with a bottom, and inside thereof there is a plunger body 41 and a plunger body 41 between which a high pressure chamber 42 is formed. 3/)<It is inserted 1^j so that it can rotate freely with the earth part protruding. The plunger 43 is forced upward by the resilient member 4/I and causes a slip, which will be described later. This prevents it from falling upward.

The plunger 13 is provided with large diameter portions 46.47 at the lower part and the center portion in the longitudinal direction, which slidably fit into the inner circumferential surface of the plunger body 41. It has a structure in which an annular groove 48 is formed between /17. Further, the upper end of the plunger 43 is formed into a hemispherical shape so as to be in rotatable contact with the lower end of the rocker arm. An annular space 49 is formed between the annular groove 48 and the inner circumferential surface of the plunge topody/11, and this space 49 is connected to the plunger 43.
It is communicated with the high pressure chamber 42 through a communication passage 50 formed in the high pressure chamber 42 . The opening of the communication passage 50 on the high pressure chamber 42 side allows only the flow of hydraulic oil from the communication passage 50 to the high pressure chamber 42 side.
A check valve 51 is provided.

The check valve 51 includes a plunger 43 that defines the high pressure chamber 42.
The ball cage 52 is attached to the bottom of the snap ring 53? ! It has a structure in which the check ball 5/I is housed in the ball cage 52.

On the other hand, the upper end of a diaphragm 55 formed in a substantially cylindrical shape on the outer periphery of the head of the plunger 43 is liquid-tightly fixed at 1M by caulking the retainer 56, and the lower end of the diaphragm 55 is attached to the outer periphery of the upper end of the plunger body 41. NiJ: is fixed in a liquid-tight manner. As a result, a reservoir chamber 57 is defined between the inner circumferential surface of the diaphragm 55 and the shoulder of the plunger t/13, and this reservoir chamber 57 is connected to the space/19 and the high pressure chamber 42 via the communication passage 58.50. It is communicated.

To explain the structure for fixing the lower end of the die refram 55 to the plunger body 41, as shown in FIGS. 4 and 5, the retainer 45 has a plurality of holes 59 provided at intervals in the circumferential direction. The ring plate 60 is composed of a cylindrical part 61 extending downward from the outer peripheral edge of the ring plate 60, and the lower end of the first part 61 is formed on the outer periphery of the small diameter part of one end of the plunger body 41. It is directly caulked and fixed in the annular groove 62. And the diaphragm 5! , 1 pass through the hole 59 of the ring plate 60 of the retainer 45 and protrude downward from the ring plate 60, and the protruding portions 55a are connected to each other.
: It is integrated with the retainer 45 and is pressed against the upper outer periphery of the plunger body/11.

2i, 1-Note] In addition to the j4 formation, if the lower end of the diaphragm 55 and the retainer 45 are bonded via adhesive, the lower end of the die 17 phragm 55 and the retainer 45 can be more firmly bonded. . Further, 63 in FIG. 3 is a plug that closes the upper part of the communication path 50.

Therefore, in the lash adjuster configured as described above, if a gap is generated between the rocker arm of the valve train and the valve train cam, the elastic portion IJ /1.
At 4, the plunger 1743, which is urged upward, moves upward and absorbs this gap. In addition, as the plunger 43 moves upward, the hydraulic oil in the reservoir chamber 57 flows into the communication passage 58.
．． 50 into the high pressure chamber 42, and at this point even if a compressive force is applied to the lash adjuster due to the operating force of the valve operating cam, etc., the high pressure chamber 7! Since the hydraulic oil that has flowed into I2 is prevented from flowing in the opposite direction by the valve 51, the entire lash adjuster remains rigid at an appropriate length and transfers the operating force of the valve drive cam via the rocker arm. to the valve.

Further, when the plunger 43 moves up and down with respect to the plunger body 41, the volume of the high pressure chamber 42 changes, but the amount of change is due to the change in the volume of the reservoir chamber 57 due to the expansion and contraction of the diaphragm 55. Absorbed.

In addition, in the lash adjuster having the above configuration, the retainer 45 has the function of bringing the lower end of the diaphragm 55 into JT contact with the plunger body 41 and the function of regulating the upper movement limit of the plungers 7!13. Therefore, the second
There is no need to provide the snap ring 10 as shown in the conventional example in the figure (and of course there is no need to provide the jt4 for fitting the snap ring 10 on the plunger body 41). 2. Compared to the conventional plunger body 41, the size of the plunger body 41 can be reduced (1), and the entire length of the plunger body 41 can be shortened.

;1: Yes, if you put it on the I-idi lash adjuster,
A plurality of holes 59 are formed in the ring plate 60 of the retainer/I5, and the lower end of the daisephram 55 is passed through the wire hole 59 to protrude, and these protruding portions 55a are connected to each other. Particularly, since the lower end of the redy A7 flamm 55 and the retainer/I5 are made into an integral structure, the lower end of the diaphragm 55 and the retainer 45 can be firmly connected, and as a result, the lower end of the diaphragm 55 and the plunger body 41 can be tightly connected. Good liquid tightness can be maintained for a long period of time.

In addition, in the embodiment described in -, the plunger body 4 related to leakage from the high pressure chamber 42 to the reservoir chamber 57
The length of the sliding portion between 1 and the plunger 43 is annular tt+
It is only the lower part of t/18, which 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 surrounding portion is made small, the resistance to leakage does not increase unnecessarily, and the desired amount of leakage can be obtained. As a result, the plunger 43 can be prevented from collapsing, thereby improving operability and durability. will improve.

Further, in the above embodiment, since there is no seal member interposed inside the lower end of the retainer 45, the retainer 45
The lower end can be caulked reliably. Note that the lash adjuster shown in FIG. 2 has a sealing member made of an elastic material interposed inside the retainer 21, which has the disadvantage that it cannot be crimped strongly.

According to the present invention, the lower end of the diaphragm is fluid-tightly pressed against the outer periphery of the plunger body.
Since the retainer is integrally provided with a ring plate that restricts the upper limit of the plunger's movement, the plunger 111
There is no need to provide special parts such as the snap ring shown in the conventional example for the 2M protection +1-, and of course there is no need to provide a groove for fitting the snap ring on the inner peripheral surface of the plunger body. In addition, as mentioned above, there is no need to provide a snap ring on the inner peripheral surface of the plunger body, so the plunge V body can be made shorter accordingly.
As a result, the entire lashco j' justa can be shortened, which is advantageous in terms of engine layout.

In addition, a plurality of holes are provided in the ring plate of the retainer, and the lower end of the Gui 17 flam is passed through the holes to protrude. If the diaphragm lower end and the retainer are made into an integral structure by connecting the kneading protruding parts to each other, it is possible to increase the bonding strength between the die rod 77 ram lower end and the retainer, and as a result, the connection between the diaphragm lower end and the plunger body can be increased. It has the effect of being able to maintain good sealing performance over a long period of time.

[Brief explanation of the drawing]

Figures 1 and 2 show a conventional example of a lash adjuster, Figure 1 is a schematic diagram of the entire valve train, Figure 2 is a longitudinal sectional view of the lash adjuster, and Figure 3 is an embodiment of the present invention. Fig. 4 is an enlarged view of the inside of 1v in Fig. 3.
The figure is a perspective view of the retainer. 1... Lash adjuster, 2... Valve, 3... Rocker arm, 4... Eel 1
Valve cam, 41...Plunger body, 42...
...High pressure chamber, 43...Plunger, 44.
...Bulging member, 45...Retainer, 48
... annular groove, 49 ... space, 51 ...
...Check valve, 55...Diaphragm, 55
a...Protruding portion, 57...Reservoir chamber, 60...Ring plate. Applicant Honda Motor Co., Ltd. 1 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] 1) A plunger body having a cylindrical shape at the bottom right, and a plunger body that is slidable with its upper part protruding into the plunger body.
A sealed hydraulic lash adjuster comprising an inserted plunger 11, a high ff chamber formed between the lower surface of the plunger and the bottom surface of the plunger body, and a liner chamber communicating with the high pressure chamber via a check valve. The upper end of a substantially cylindrical diaphragm defining the reservoir chamber inside is fluid-tightly fitted onto the outer periphery of the protruding upper part of the plunger, and the lower end of the diaphragm is fitted onto a retainer disposed outside. A sealed hydraulic lash adjuster, which is brought into liquid-tight pressure contact with the upper outer periphery of a plunger body, and the retainer is integrally provided with a ring plate that regulates the upper limit position of the plunger. 2) a plurality of holes are formed in the ring plate of the retainer;
The lower end of the diaphragm passes through this hole and projects downward from the ring plate, and the projecting portions are connected to each other and pressed against the upper outer periphery of the plunger body. Sealed hydraulic lash adjuster as described.