JP2576871Y2 - Reciprocating rod drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a reciprocating rod drive device for transmitting reciprocating motion to a reciprocating member such as a diaphragm in a diaphragm type vacuum pump, and particularly to a bifurcated base of a rod. By arranging the respective cam sliding portions provided in the axial direction of the rod via the cam shaft, the drive device can be made more compact by mounting the forward drive cam and the return drive cam on the same cam shaft. There is no direct interference between the forward drive cam and the backward drive cam, and each cam can use two-sided, three-sided, and four-sided cams with 180 °, 120 °, and 90 ° phase, and double the rod reciprocating movement. To plan.

[Conventional technology]

In this type of reciprocating rod driving device, as a conventional device, a valve opening (forward drive) cam mounted on one cam shaft and a cam shaft mounted on the other cam shaft within a frame integrated with a valve rod. A shortened intake / exhaust valve forced opening / closing device in which the distance between the valve and the cam is shortened by providing a valve closing (returning) cam adjacent to the valve stem in the same phase in the axial direction is known. (See, for example, JP-A-59-5817).

[Problem to be Solved by the Invention] In the above-mentioned conventional shortened intake / exhaust valve forced opening / closing device,
A valve-opening cam mounted on one camshaft and a valve-closing cam mounted on the other camshaft are installed adjacent to each other in the same phase in the axial direction of the valve stem within a frame integral with the valve stem. Since not only two camshafts are required as drive shafts for transmitting reciprocating motion to the valve stem, but also two camshafts are arranged in the axial direction of the valve stem, There is a problem that the device becomes large, and the valve-opening cam and the valve-closing cam, which are respectively mounted on the camshafts at regular intervals, are opposed to and adjacent to each other. Because the direct interference area of the is large and the cam shape is restricted, only monotonous reciprocating drive can be expected.

The present invention solves the above-mentioned problems of the prior art, and the forward drive cam is provided by disposing each cam sliding contact portion provided on the bifurcated base of the rod in the axial direction of the rod via a cam shaft. In addition to reducing the size of the drive by mounting the return drive cam on the same cam shaft, there is no direct interference between the forward drive
It is an object of the present invention to provide a reciprocating rod driving device capable of doubling a rod reciprocating motion by using a plurality of cams such as a two-sided, three-sided, or four-sided cam having a phase of 0 ° and 90 °. .

[Means for solving the problem]

In order to achieve the above object, the reciprocating rod driving device of the present invention includes a rod supported reciprocally by a rod support, and a cam shaft having a forward drive cam and a return drive cam on the same axis, A base portion of the rod is formed in a forked shape, and a cam sliding contact portion is provided on each of a lower end portion of one of the forked base portions and an upper end portion of an arm extending to the other base portion. A forward driving cam and a backward driving cam on the cam shaft are disposed at the cam sliding portion so as to face each other in the axial direction of the rod.

[Action]

In the reciprocating rod driving device configured as described above, each of the cam sliding contact portions provided on the bifurcated base of the rod slidably reciprocated on the support body coaxially moves the forward drive cam and the backward drive cam. It is disposed in the axial direction of the rod via the cam shaft provided above, and is opposed to the forward drive cam and the backward drive cam. By shifting the phase with the cam,
The rod is moved forward and backward by the forward drive cam, and reciprocated by the backward drive cam. The forward drive cam and the backward drive cam are mounted on the same cam shaft and the cam shaft is one.
Since this is a book, the drive device can be made compact by simplifying the drive mechanism, and there is no direct interference between the forward drive cam and the backward drive cam. The two-sided cam can be used, and by shifting the phase between each two-sided cam by 90 °, the rod can reciprocate two times for one rotation of the camshaft.
Double reciprocation of the rod can be realized.

〔Example〕

The embodiment will be described with reference to the drawings. In the embodiment, the reciprocating rod driving device according to the present invention is applied to a diaphragm type vacuum pump, and 1 is a pump case 2 and a case cover 3 which is a rod support. The diaphragm whose peripheral portion is clamped by the
A pump chamber 4 is constituted by the pump case 2, and the pump case 2 has a suction hole 6 having a suction check valve 5.
A discharge hole 8 having a discharge check valve 7 is formed, and a rod support hole 9 is formed in the center of the case cover 3 and an air hole 10 is formed in the periphery thereof.

A rod 12 having a base 11, 11 'formed in a forked shape is supported in a rod supporting hole 9 formed in the case cover 3 so as to be able to reciprocate freely. The mounting plate 14 is fixed to the center of the diaphragm 1 held by the holding plates 13, 13, and the lower part of one of the forked bases 11, 11 ′ of the rod 12 is a cam sliding part. A roller 15 is pivotally mounted, and a U-shaped arm 16 is further extended to the other base 11 '. A roller 17 serving as a cam sliding contact portion is provided on an upper end of the arm 16 at an end thereof. Is pivoted. A cam shaft 18 is provided between each of the rollers 15 and 17, and a forward drive cam 19 facing the roller 15 and a return drive cam 20 facing the roller 17 are mounted on the cam shaft 18. By the sliding contact between the forward drive cam 19 and the roller 15 and the sliding contact between the return drive cam 20 and the roller 17 due to the rotation of 18,
The rod 12 is reciprocated in the rod support hole 9 so that each roller
The cam shafts 18 interposed between the rollers 15 and 17 and the rollers 15 and 17 are arranged in the axial direction of the rod 12.

Since the embodiment is constructed as described above, the forward drive cam 19 slides on the roller 15 which is a cam sliding contact portion to drive the rod 12 forward by rotation of the cam shaft 18, and the return drive The cam 20 slides on the roller 17 serving as a cam sliding contact portion to drive the rod 12 back, and the rod 12 is guided by the rod support hole 9 and reciprocates. The pump of the diaphragm 1 accompanying the reciprocation of the rod 12 By the action, the medium sucked from the suction hole 6 is discharged from the discharge hole 8 through the suction check valve 5 and the discharge check valve 7, but the forward drive cam 19 and the return drive cam 20 are one Since the drive unit is mounted on the camshaft 18, the drive unit can be made compact without bulky as compared with the case of two camshafts.
In addition to the use of a one-sided cam for the forward drive cam 19 and the backward drive cam 20 shown in the figure, since there is no direct interference between the forward drive cam 19 and the backward drive cam 20, the 180 ° shown in FIGS.
It is possible to use the forward drive cam 19 'and the backward drive cam 20' composed of a two-sided cam having a phase, and the phases of the forward drive cam 19 'and the backward drive cam 20' composed of the two-sided cam are shifted by 90 °. When mounted, pump performance can be improved by doubling the rod reciprocation.

Also, the forward drive cam 19 "and the backward drive cam 20", each of which is a 120 ° phase three-sided cam shown in FIGS. 6 and 7, and a 90 ° phase four-sided cam shown in FIGS. 8 and 9. A plurality of cams such as the forward drive cam 19 and the backward drive cam 20 can be used, and double reciprocation of the rod can be achieved.

Although the embodiment has been described with reference to the case where the reciprocating rod driving device according to the present invention is applied to a diaphragm type vacuum pump, it is needless to say that the reciprocating rod driving device can also be applied to a piston pump, a compressor, a fuel pump or the like.

[Effect of the invention]

The present invention is configured as described above. Each of the cam sliding contact portions provided on the bifurcated base of the rod slidably reciprocated on the support body includes the forward drive cam and the return drive cam. The reciprocating motion of the rods is the same because they are arranged in the axial direction of the rod via a cam shaft having a driving cam on the same axis, and face the forward driving cam and the backward driving cam. Since it is driven by a cam mechanism which is a mechanism, the reciprocating motion of the rod can be powerfully and accurately driven, and the forward drive cam and the backward drive cam are mounted on the same cam shaft and there is only one cam shaft. The drive mechanism can be made compact by simplifying the drive mechanism, and there is no direct interference between the forward drive cam and the backward drive cam. Phase two-sided, three-sided, four-sided cams, etc. It is possible to double the reciprocating movement of the rod by using the multiple surface cam.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a partial sectional front view in which the reciprocating rod driving device according to the present invention is applied to a diaphragm type vacuum pump, and FIG. 2 is a diagram of the reciprocating rod driving device in FIG. FIG. 3 is a left side view, FIG. 3, FIG. 6, and FIG. 8 are left side views of a reciprocating rod driving device showing another embodiment, FIG. 5, FIG. The figure is also a right side view. 3 ... Bearing body, 11, 11 '... Bifurcated base 12 ... Rod, 15, 17 ... Cam sliding contact part 18 ... Cam shaft, 19, 19', 19 ", 19 ... Forward drive cam 20 , 20 ′, 20 ″, 20 …… Return drive cam

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yuichiro Takaishi 8 Isuzu Motors, Fujisawa City, Kanagawa Prefecture Inside Isuzu Motors Co., Ltd. (72) Inventor Mitsuo Hattori 8 Isuzu Motors, Fujisawa City, Kanagawa Prefecture Isuzu Motors Limited Inside the Fujisawa Plant (72) Ryoichi Tochizawa 3-25-1, Tonomachi, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Isuzu Motor Co., Ltd. Inside the Kawasaki Plant (72) Inventor Atsushi Takeda 8-Tsuchiya, Fujisawa City, Kanagawa Prefecture Isuzu Motors Limited Inside the Fujisawa Plant (72) Inventor Masaji Kato 8 clay bowls in Fujisawa City, Kanagawa Prefecture Inside the Fujisawa Plant Co., Ltd. (72) Inventor Satoshi Hokari 8 clay bowls in Fujisawa City, Kanagawa Prefecture Inside the Fujisawa Plant Ltd. (72) The creator, Minoru Watanabe, Isawa Motor Co., Ltd., Fujisawa Plant, No. 8 Dosana, Fujisawa, Kanagawa Prefecture (72) Proposer Toru Hayasaka 1-12-14-1004, Minami Kamata, Ota-ku, Tokyo (56) References JP-A-59-5817 (JP, A) JP-A-58-195082 (JP, A) Jikken 47-34111 (JP, Y1) (58) Field surveyed (Int. Cl. ⁶ , DB name) F16H 25/14 F04B 9/04

Claims (1)

(57) [Scope of request for utility model registration] 1. A rod supported reciprocally by a rod support, and a cam shaft having a forward drive cam and a return drive cam on the same axis. The base of the rod is formed in a forked shape. A cam sliding portion is provided on each of a lower portion of one of the base portions and an upper portion of an end portion of an arm extending from the other base portion, and each of the cam sliding portions is a forward drive cam on the cam shaft. A reciprocating rod driving device, wherein a reciprocating cam and a return driving cam are disposed so as to face each other in the axial direction of the rod.