JPS5848807A - Method and apparatus for measurement of multicoupled cams - Google Patents

Abstract

PURPOSE:To efficiently measure the height between each cam and journal of multicoupled cams, by using levers abutted on the peripheral bottom of cams and journals and detecting the displacement of the levers at the rotation of a cam shaft. CONSTITUTION:A cam shaft T to be measured is rotated while being put between a driving shaft 18 in a driving part 5 and a floating shaft (not shown in a figure) in a driven part 6 having the same constitution as the driving part 5. Plural measuring levers 11 are pivotally supported approximately horizontally on positions opposed to respective cams C and journals J. Each lever is energized upwards by a spring 12 and the leading end of the lever is abutted on the peripheral of the cams and journals with a prescribed measuring pressure. The difference of the height between the peripheral surface of each cam and that of the opposed journal is measured by detecting the displacement of the lever with a differential transformer 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for measuring multiple cams that form a component of a valve clearance measuring machine and are used to measure the height of a valve train cam base.

When the cylinder head of an automobile engine is assembled, for example, as in the case of the four-cylinder cylinder head W shown in Figs. 1 and 2, a plunger-shaped glue lid L is fixed to the top of the stem E of each exhaust valve A shim S (shown in Fig. 2) is fitted onto the dished upper surface of the lifter L to adjust the clearance between it and the cam C formed on the camshaft T. .

However, in the assembly process of the cylinder head W, various types of numerals with different thicknesses are supplied, and when assembling the camshaft T, each cylinder head W is supplied with different thicknesses.
It is necessary to select and use a shim S with a thickness that corresponds to the assembly dimensions of each valve V, and from this, the actual valve clearance BC, that is, the cam C base height HB and the lifter L'' height across surfaces. The shim S to be used is determined by measuring the height of I- from HL.

By the way, there are two conventional clearance BC inspection methods, a direct method and an indirect method.In the direct method, first, after temporarily assembling the cam shirt T,
A hand-held gauge is used to directly measure the gap, and this method not only requires a lot of effort, but also has the drawback of not being able to achieve high accuracy.

On the other hand, in the case of the indirect method, the cylinder head W is located at a height d between the height HJ of the bearing surface F of the shaft journal J (actually, the inner peripheral surface of the bearing) and the height HL of the upper surface of the lifter L. In addition, regarding the camshaft T, the height d2 between the journal J circumferential quotient height HJ and the cam C base circumferential surface height HB is measured, and the clearance BC is determined by calculating the difference between constant values on both sides.However, conventionally, height dl,
d2 was measured manually for each valve using a reference jig, etc., which saved the trouble of temporarily assembling the T-shirt, but it also required more effort.
As a result, it has been difficult to improve the productivity and assembly quality of the cylinder head W, and this tendency has been particularly pronounced in multi-cylinder engines.

The present invention has been made in view of the current situation, and an object of the present invention is to set the base circumferential height H of each cam based on the journal circumferential height HJ of the multiple camshaft.
An object of the present invention is to provide a method and device for measuring multiple cams that can mechanically and simultaneously measure B.

The present invention will be described below based on an illustrated embodiment.

The cam base height measuring device as the cam measuring device of the embodiment forms part of the structure of the valve clearance measuring device shown in Figs. It forms one half.

In addition, as a mechanism related to the entire measuring machine, a control calculation mechanism 1 having a long cylindrical outer shape is installed in two stages, and
At the lower stage of the measuring machine, a cross rail 2 for conveying the cylinder head W as a workpiece and a mechanism for driving the conveyance thereof are arranged.

By the way, the cam base height measuring device 3 is formed by a measuring section 4 in the center, a driving section 5 on the left side j5, and a driven section 6 on the right side, and the formation mode of each part will be described below.

(a) Measuring part 4 On the front side of the central part, bearing jigs 7 and 8 for supporting both ends of the cam shirt (T) as a workpiece are erected, and
Each cam C is mounted on a support shaft 10 horizontally suspended on a support stand 9.
and multiple (cam 8
, 5 for journals, 13 in total) measuring levers 11 are pivoted almost horizontally.

Therefore, each lever 11 is moved by the elasticity of the push-up spring 12 interposed between the lower surface in front of the support shaft 10 and the spring hole 9a of the support base 9, so that the front end of the lever 11, that is, the measurement end 1],
The camshaft T is rotated in the direction of raising a, but the camshaft T is attached to the jig 7°8 (see Figure 7).
Here, the measurement end 11a is in contact with the bottom of the cam C or the bottom of the first circumference of the journal, using the biasing pressure of the spring 12 as the measurement pressure.

Further, a measuring pin 14 of a differential transformer 13 as a length measuring device fixed to a mounting hole of an overhang 9a of the support base 9 is in contact with the lower surface of the rear end of each measuring lever 11.

In addition, a photoelectric detection unit 15 whose optical path is blocked by the nose of the cam C is arranged near the front end of at least one cam measuring lever 11 (the fifth bar 17 from the left in the figure). This serves as an information source for setting the rotational position of the camshaft T.

(1)) Drive unit 5 Sleeve 1 attached between vertical plates 16 at two locations on the left and right
A transmission shaft 18 for driving the workpiece is inserted into the inner hole of the sleeve 16, and the transmission shaft 18 is driven by an air cylinder 19 installed in parallel with the sleeve 16 and an operation sliding plate that moves from side to side. The bearing is held at 20.

Therefore, the tip of the transmission shaft 18 on the side of the bearing jig 7 is formed with a conical head that approaches and separates from the conical concave surface formed on the end surface of the cam shirt L-T, so that the transmission shaft 18 moves to the right. In the illustrated state (No. 51), the coaxial shaft 18 is rotatably connected to the camshaft T, and in the leftward movement state, the camshaft T can be freely removed from the jig 7.

Furthermore, a boot 1J21 is pivoted near the head of the transmission shaft 18, and an intermediate shaft 23 on which a pulley 22 is pivoted is supported at the rear of the sliding plate 20. Both pulleys 21
, 22, and the intermediate shaft 23 is driven by an operation drive mechanism (not shown).

(C) Follower part 6 Similar to the transmission shaft 18 described above, a floating shaft (not shown) is provided which is driven by an air cylinder and slides left and right. It is formed to come into contact with and separate from it.

Note that the drive section 5 and the driven section 6 are covered by a cover 24 and a cover 25, respectively.

Here, an overview of the valve lifter height measuring mechanism 26 attached to the above-mentioned cam base height measuring device 3 will be explained.

The measuring mechanism 26 consists of a beam 28 and a frame 29 that can freely swing around a support shaft 27, and a movable plate 31 suspended from a base plate 30 attached to the frame 29 is equipped with a workpiece W. The same number of differential transformers 32 as the valves ■ are mounted downward, and a pair of probes 33 connected to the measuring pins of each differential transformer 32 are in contact with the upper surface of each valve lifter L. .

Note that when the movable plate 31 is lowered onto the workpiece W, the reference legs 34 at both ends of the lower surface of the movable plate 31 and the intermediate leg 3 at the center
5 is in pressure contact with each bearing surface F of the workpiece W with strong elasticity.

The operation of the cam measuring device according to the embodiment with the above-mentioned configuration will be explained below.The premise is that the entire valve clearance measuring device operates, and that the workpiece W, on which the valve V has been assembled, is moved from the right side of the rail 2. At the same time as being fed onto the rail 2, the camshaft T as a material part is inserted onto the bearing jigs 7 and 8 by hand by an operator, and then the lifter height measuring mechanism 26 is operated and the cam base height is measured. Device 3
The operation is carried out in parallel.

Furthermore, with the attached valve lifter height measuring mechanism 26, c.
The height of the two sides of the lifter LJ of each valve ■, that is, the height d1
is measured by each actuation transformer 32, the measured value is recorded in the control calculation mechanism 1, and further after recording, the workpiece W has been moved to the left end of the rail 2.

After the conveyance of the workpiece W onto the rail 2 is detected at times t, ro, and the measured amount fA, all the operations of each part are processed based on the commands of the control calculation mechanism l. .

By the way, the material parts cam shirt) T are bearing jigs 7 and 8.
When the cams C are inserted into the camshaft T, the cam bases of all the cams C do not face the open bottom. A reference direction (hereinafter referred to as reference angle) has been determined, and in actual measurement, the base of all cams is measured twice for each reference angle. and the direction angle of the nose of the specific cam detected by the photoelectric detection unit 15 are stored in the control calculation mechanism 1 in advance.

When the measurement is commanded to the mechanism 1, first, each cylinder 19 of the driving part 5 and the driven part 6 is operated to protrude, and the transmission shaft 18 and the floating shaft on both sides are rotationally connected to the shirt T. Then, the nose direction of the specific cam is detected during one rotation of the transmission shaft 18, and when the reference angle close to the detected nose direction is reached, the transmission shaft 18 stops, and the shaft T
It is set to the reference angle of the second time.

After the transmission shaft 18 is stopped as described above, each differential transformer 13 for the first measurement operates and the measured value is recorded in the control calculation mechanism 1, and the measured value of each cam C is The difference was calculated with the measured value of both side journals J]=,
It is recorded as a height d2 for each cam C.

Next, after the camshaft T is driven and set to the reference angle of [1] twice in the same way, the measured values of each cam C and the calculated value (d2) for the second measurement are recorded. , the height d2 of all cams is recorded, and after that recording, the transmission shaft 18 and the idle shaft are moved away from the camshaft T by the retraction operation of the cylinder 19.

In addition, the cam shirt (T) removed from the bearing jigs 7 and 8 is
Together with the workpiece W on the left end of the rail 2, it is sent to the next process.

Therefore, in the control calculation mechanism 1, the recorded height d
, , d2 are recorded, each valve clearance B'C is calculated based on the difference calculation of the above two heights d, , d2 for each valve V, and then the corresponding clearance BC value is calculated. The type of shim that has been installed is searched, its type symbol is recorded, and the same symbol is displayed in the next step of attaching the shim S to the lifter L.

As described above, according to the method and apparatus for measuring multiple cams according to the present invention, a unique length measuring device is connected to each cam circumferential surface of the multiple cam and each of the journal circumferential surface of the camshaft. The height of the cam circumferential surface and the height of the journal circumferential surface at a predetermined rotational phase angle are measured by bringing the measuring end of the measuring lever that has been Since the height of the cam is measured, it becomes possible to measure the height in a short span, and also to measure it efficiently, which has the effect of improving the ease of assembling the multiple cam.

[Brief explanation of the drawing]

FIG. 1 is a side view of a cylinder head illustrating the manner in which multiple cams are assembled, FIG. 2 is a rear sectional view taken along line ■-n in FIG. 1, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a left side view of the multi-cam measuring device, FIG. 5 is a cross-sectional plan view taken along line V-V in FIG. 3, and FIG. The partial front view in Fig. 7 is the partial front view in Fig. 5.
FIG. C...Cam, J...Journal, T...Camshaft, 1...Control calculation mechanism, 7, 8...Bearing jig, 1
1... Measuring lever, Ila... Measuring end, 13... Differential transformer as a length measuring device, 14... Measuring pin, 15
... Photoelectric detection unit, 18 ... Drive transmission shaft. Agent: Patent attorney Norihiro Nishimura m, r HL --- 2nd:/I

Claims (3)

[Claims] (1) In the multiple cam measurement method for measuring the height of each cam circumferential surface with reference to the circumferential surface of the shaft journal for a camshaft in which many cams are molded in parallel on the axis, With both ends supported on bearing jigs, each measuring end of a plurality of unique length measuring devices is brought into contact with each cam circumferential surface and each journal circumferential surface, and the camshaft is After setting the rotation phase angle to a predetermined value, measure the radial height of the circumferential surface of each cam with a length measuring device, and calculate the difference between the measured values to calculate the height of each cam circumferential surface. - A method for measuring a multiple cam, characterized in that the height from the reference standard is measured. (2) On the axis (for a camshaft in which a large number of cams are molded in parallel, a multiple cam measuring device for measuring the height of each cam surface with respect to the circumferential surface of the shaft journal, a bearing jig supporting both ends; a plurality of measuring levers aligned with each other with one movable end in contact with each cam river bed and each journal stratification by rotational behavior; Each length measuring device has a measuring bottle in contact with its moving end, a control calculation mechanism that calculates the difference between the measured values electrically output from each length measuring device, and a shaft drive that sets the camshaft at a predetermined rotational phase angle. and the calculation mechanism is configured such that the measured value of each cam river bed is compared with the measured value of the adjacent journal stratification. measuring device. (3) In the shaft drive means described above, at least one cam is provided with a charge detection unit that is shielded from light by its nose, and this allows the camshaft to adjust to the phase angle that makes the cam base face the cylinder bottom. A multiple cam measuring device characterized in that it is configured to be driven.