JP5465885B2 - Cylinder variation adjustment jig - Google Patents

Description

  The present invention relates to a cylinder variation adjusting jig used for adjusting variation among cylinders of a variable valve assembly.

Recently, in a reciprocating engine (internal combustion engine) installed in an automobile, the valve drive output of an intake valve is continuously controlled by a cylinder head in order to prevent engine exhaust gas and improve pumping loss. A variable valve system is being installed.
In many variable valve systems, at least the valve lift amount of the intake valve is continuously changed in order to adjust the intake air amount. For example, as disclosed in Patent Document 1, the valve drive output of the intake cam formed on the camshaft is continuously changed from the low valve lift to the high valve lift and transmitted to the valve drive member, and the intake valve is controlled. There is a structure to drive.

By the way, normally, the valve system of an engine has assembled each member of a valve system for every cylinder using the head assembly line which assembles a cylinder head. Therefore, the assembly of the variable valve system is also assembled to the cylinder head that flows through the head assembly line.
However, since the variable valve system has a large number of work steps, it places a considerable burden on the head assembly line.

Therefore, by applying the technique for assembling the rocker arm assembly disclosed in Patent Document 2, a variable valve assembly having a camshaft, a valve drive member, and the like is assembled at a location different from the head assembly line. It can be considered that the valve assembly is assembled to the cylinder head after the intake valve has been assembled.
By the way, unlike the rocker arm assembly as disclosed in Patent Document 2, the variable valve assembly varies the valve characteristics, so that the valve lift characteristics between the cylinders are required to be uniform. In particular, a variable valve assembly that has only been assembled greatly varies in valve lift characteristics between cylinders. For this reason, the variable valve assembly requires adjustment of variation among cylinders to suppress variation in combustion among the cylinders.

Here, the variable valve-to-cylinder variation adjustment of the variable valve system (not assembled) is performed while the variable valve system is assembled to the cylinder head as disclosed in Patent Document 3. The lift amount of the valve driven by is measured with a sensor and adjusted so that the valve characteristics between the cylinders are uniform.
For this reason, it is conceivable that the variable valve assembly including the camshaft and the valve driving member is also adjusted after being assembled to the cylinder head.

JP 2005-299536 A JP-A-10-249656 JP 2008-75613 A

  However, the variable valve assembly is complicated because it includes a camshaft and a valve drive member. In addition, the upper part of the cylinder head on which the variable valve assembly is mounted is considerably complicated with various parts. It is difficult to even set the valve close to the valve, making it difficult to secure a system that can measure. For this reason, the work for adjusting the variation between cylinders is considerably burdensome to the operator.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a cylinder variation adjusting jig that can easily perform a variation adjusting operation between cylinders.

In order to achieve the above object, a first aspect of the present invention provides a camshaft including an intake cam, a valve drive member for each cylinder that drives a valve, and a swing cam that transmits displacement of the intake cam to the valve drive member. Between the cylinders of the variable valve assembly, which is used in a variable valve assembly assembled so that the cam displacement of the swing cam relative to the intake cam can be varied by the advancement / retraction of the adjusting screw and output from the valve drive member A cylinder variation adjusting jig for adjusting variation, which is provided on a jig main body for mounting a variable valve assembly in which a protruding amount of an adjusting screw is uniformly adjusted for each cylinder. and a lift sensor, lift sensor are respectively provided corresponding to each position of the valve driving member when was equipped with a variable valve assembly to the jig body, adjusting the sensitivity Measuring the valve lift amount output from the valve driving member in adjustment work performed by the variable valve assembly to adjust the adjustment followed by lift position of the low adjustment sensitivity low valve lift side lift position of the high high valve lift side It was decided to.

  That is, the variable valve assembly has a camshaft that serves as an input portion for cam displacement and a valve drive member that serves as an output portion for valve driving force so that the cam displacement can be varied. Unlike an assembly with only a rocker arm mechanism, the variable valve assembly can be adjusted only with a variable valve assembly. Therefore, in consideration of this characteristic, the adjustment work for the variation between cylinders is not performed by the cylinder head, but is performed by using a dedicated adjustment jig that reproduces the assembly equivalent to the cylinder head. The use of a dedicated adjustment jig eliminates the need for troublesome setup work, such as securing a place to set a sensor and adjusting the measurement system, such as when adjusting cylinder variation by assembling the cylinder head. In addition, it is possible to adjust the cylinder variation of the variable valve assembly.

According to the second aspect of the present invention, the valve drive member has a screw portion that comes into contact with the valve at the tip thereof, and the jig body has a protruding amount of the screw portion from the tip of the valve drive member for each cylinder. And a lift sensor is provided corresponding to each position of the screw portion of the valve drive member when the variable valve assembly is mounted on the jig body. did.
According to the third aspect of the present invention, the lift sensor includes a displacement member that displaces following the movement of the valve driving member, and a displacement amount of the displacement member so that the valve lift amount can be measured with a simpler structure. And a configuration having a detection unit for detecting.

According to the first and second aspects of the invention, the adjustment jig with a dedicated lift sensor that reproduces the assembly equivalent to the cylinder head eliminates the need for troublesome setup work such as when the cylinder head is assembled. It is possible to adjust the cylinder variation of the variable valve assembly.
According to the invention of claim 3, the lift amount of the valve can be measured with a lift sensor having a simple structure.

The perspective view which shows the cylinder dispersion | variation adjustment jig which concerns on one Embodiment of this invention with the variable valve assembly to be adjusted. The perspective view which shows the state when the variable valve assembly is assembled | attached to the cylinder variation adjustment jig. Sectional drawing in alignment with the AA in FIG. Sectional drawing explaining cylinder dispersion | variation adjustment work. The diagram which shows the valve lift height at the time of valve lift large. The diagram which shows the valve lift height when it replaces at the time of valve lift small.

Hereinafter, the present invention will be described based on an embodiment shown in FIGS.
FIG. 1 shows an adjustment jig 40 (corresponding to the cylinder fluctuation adjustment jig of the present application) used for adjusting the fluctuation between cylinders of the assembly 1 used in a multi-cylinder engine to be subjected to adjustment of cylinder-to-cylinder variation. 2 shows a state when the variable valve assembly 1 is assembled to the adjustment jig 40, and FIG. 3 shows a cross-sectional view (A-A line in FIG. 2) at that time. .

Here, before explaining the method for assembling and adjusting the variable valve assembly 1, the structure of the variable valve assembly 1 to be adjusted will be described.
As shown in FIGS. 1 to 3, the variable valve assembly 1 includes a plurality of holder members 2 arranged along a cylinder row at an inter-cylinder pitch, and a support shaft 10 that extends over the upper part. An exhaust rocker shaft 12 is assembled on one side to form a frame, and a control shaft 13 also serving as an intake rocker shaft is rotatably assembled between holder members 2 on the intake side (opposite side of the exhaust rocker shaft 12) of the frame. Further, the camshaft 17 is rotatably assembled to the lower part of the holder member 2 with a cam cap 15. In addition, an intake rocker arm 22 (corresponding to a valve driving member of the present application) that drives an intake valve (not shown) is rotatably assembled to the control shaft 13 for each cylinder. Further, as shown in FIG. 3, the valve characteristics of the intake cam 17a can be varied between the intake rocker arm 22 and the intake cam 17a of the camshaft 17 for each cylinder. A variable valve mechanism 19 that is variable according to the 13 rotational displacements is assembled. The variable valve mechanism 19 has an inter-cylinder variation adjusting screw 35 that adjusts the variation between cylinders. The exhaust rocker shaft 12 is assembled with an exhaust rocker arm 20 (not shown) for uniquely opening and closing an exhaust valve (not shown), and an input for inputting a valve lift is provided at one end of the control shaft 13. Part, for example, a worm-type speed reducer part 4 (consisting of a worm wheel 4a and a worm shaft 4b) is assembled. Reference numeral 4c denotes a fixing bolt for fixing the worm wheel 4a to the end of the control shaft 13. Further, for example, the worm wheel 4 a is assembled with a stopper portion 7 that defines the minimum valve lift position of the control shaft 13. Further, a control shaft displacement detection sensor (not shown) for detecting the rotational displacement of the control shaft 13 is assembled to the other end portion of the control shaft 13.

Further, the variable valve assembly 1 will be described. The variable valve mechanism 19 includes a swing cam 25 whose one end is swingably supported by the support shaft 10 as shown in FIG. A structure in which an L-shaped center rocker arm 27 interposed between the lower portion of the cam 25 and the intake cam 17a is used is used.
That is, as shown in FIG. 3, the rocking cam 25 has a cam surface 25a extending in the rocking direction at the other end and a roller 25b at the bottom. Of these, the cam surface 25 a is in rolling contact with the roller 22 a assembled to the proximal end portion of the intake rocker arm 22.

  As shown in FIG. 3, the center rocker arm 27 has a slope 28 on the tip surface of the arm portion 27 a going upward, and a bendable pin member 29 on the tip portion of the arm portion 27 b going to the control shaft 13, A rotatable roller 30 is provided at a portion where the arm portions 27a and 27b intersect. Of these, the slope 28 is in rolling contact with the roller 25b of the swing cam 25, and the roller 30 is in rolling contact with the cam surface of the intake cam 17a. The pin member 29 is inserted into a through hole formed in the control shaft 13 so as to freely advance and retract. By this insertion, the center rocker arm 27 is swingably supported with the bent portion of the pin member 29 as a fulcrum, and when the control shaft 13 is rotationally displaced, the center rocker arm 27 as a whole changes the rolling contact position with the intake cam 17a. However, the cam surface of the intake cam 17a is displaced in the advance direction or the retard direction. This displacement changes the posture of the swing cam 25 to change the region of the cam surface 25a on which the roller 22a rolls, and the valve drive output (cam displacement) output from the intake cam 17a, for example, the valve of the intake valve 17a. The lift amount, opening / closing timing, and opening / closing period are continuously varied (from the low valve lift phase to the high valve lift phase). This variable valve drive output is transmitted to the intake rocker arm 22 and is applied to an intake valve (not shown) from an adjustment screw portion 22b (a portion in contact with the valve) at each tip of the intake rocker arm 22. Further, the cylinder-to-cylinder variation adjusting screw 35 described above is screwed into the through hole into which the pin member 29 is inserted so as to be able to advance and retract, and when the adjusting screw 35 is advanced and retracted, the protruding amount of the pin member 29 is increased. Changes and the valve lift can be adjusted.

  Such a variable valve assembly 1 (including the camshaft 17) is assembled and assembled at a location different from the line for assembling the cylinder head. However, since it is only assembled, the valve characteristics between the cylinders are not uniform. It varies. If it varies, the engine combustion varies between cylinders. Therefore, the assembled variable valve assembly 1 is required to adjust the variation among the cylinders.

The adjustment jig 40 is used to adjust the variation among cylinders. As the adjustment jig 40, for example, a box-shaped jig corresponding to the cylinder head of the engine as shown in FIGS. 1 to 3 is used.
Here, the adjustment jig 40 will be described. The jig 40 has an elongated main body 40a corresponding to the cylinder head corresponding to the number of cylinders of the engine (corresponding to the jig main body of the present application) as shown in FIG. And the set part 41 for arrange | positioning the variable valve assembly 1 is formed in the upper center of the said main body 40a. The set portion 41 is formed by combining, for example, a recessed portion 40b formed along a portion where the variable valve assembly 1 is disposed, and a plurality of columnar seats 42 disposed around the recessed portion 40b. Composed. The receiving seat 42 is a portion for placing the leg portions 2 a on both sides of the holder member 2 of the variable valve assembly 1. The receiving seat 42 is formed with a knock pin 43 that can be inserted into the bolt hole 2b formed at the end of the leg 2a so that each holder member 2 is positioned at a fixed position. Thus, the variable valve assembly 1 is assembled to the set portion 41 in the same posture as when mounted on the cylinder head. A lift sensor 45 for measuring the valve lift amount output from the intake rocker arm 22 is embedded at each position where the intake rocker arm 22 is disposed in the recessed portion 40b. These lift sensors 45, for example, as shown in FIG. 3, advance and retract a bottomed cylindrical advance / retreat member 46 (equivalent to the displacement member of the present application) that extends toward the adjust screw 22b of the intake rocker arm 22 like an intake valve. A possible built-in structure is used. The advance / retreat member 46 is assembled with a spring member 47 that urges upward so that a preload is generated at zero valve lift. Thereby, the advance / retreat member 46 is adapted to advance and retract following the movement of the intake rocker arm 22. Further, the advancing / retreating member 46 is assembled with a detecting element 48 (corresponding to the detecting portion of the present application) for detecting the amount of displacement of the advancing / retreating member 46. The valve lift amount (valve lift amount of the intake valve) output from () is detected, and the valve lift height can be measured from the detected value.

In addition, at the point where the exhaust valve of the set part 41 is disposed (exhaust side), an extendable holder 49 that receives the end of the exhaust rocker arm 20 is embedded.
Next, the inter-cylinder variation adjustment work of the variable valve assembly 1 will be described using the adjustment jig 40 configured as described above.
The variable valve assembly 1 assembled in the previous process is only assembled, and the valve characteristics between the cylinders are not uniform.

  Therefore, first, when adjusting the variation between cylinders, the specifications are set to be constant for each cylinder. For this purpose, the protruding amount of the inter-cylinder variation adjusting screw 35 of each variable valve mechanism 19 and the protruding amount of the adjusting screw portion 22b of each intake rocker arm 22 are uniformly matched. And these dispersion | variation adjustment screws 35 and adjustment screw part 22b are temporarily fixed.

  When the operation is completed, the variable valve assembly 1 is assembled to the adjustment jig 40. For example, as shown in FIG. 1 to FIG. 3, first, the end of the leg portion 2 a having the bolt hole 2 b is placed on the seat 42 while fitting the bolt hole 2 b of each holder member 2 to the knock pin 43. Thereby, the adjustment screw part 22b which is an output part of each intake rocker arm 22 is positioned at the front-end | tip part which the lift sensor 45 protruded, as FIG. 3 shows. Thus, each lift sensor 45 is elastically brought into contact with the tip of each adjustment screw portion 22b, and a system for receiving the output from the intake rocker arm 22 is prepared. Subsequently, the variable valve assembly 1 is fixed. For this, for example, a bolt member 37 (shown in FIG. 1) used for fixing the support shaft 10 or a bolt member 38 (only a part of which is shown in FIG. 3) used for fixing the exhaust rocker shaft 12 is used. . For example, as shown in FIG. 1, the bolt members 37 and 38 are inserted from the rocker shaft fixing holes 2 c (only for the bolt member 37) formed in the holder member 2, so that the set portion 41 is formed. The screw hole 41a (shown in FIG. 1) is screwed and tightened with a specified torque. As a result, the variable valve assembly 1 is equivalent to a cylinder head in which the lift sensor 45 and the holder 49 replace the intake valve and the exhaust valve, and the bolt members 37 and 38 attached to the cylinder head are used as they are as fixing bolts. It is set on a dedicated adjustment jig 40 while reproducing the assembly.

  When the variable valve assembly 1 has been set (mounted), the cylinder variation adjustment operation is started. This is done by first adjusting the valve lift height at an arbitrary lift position on the high valve lift side. Specifically, first, the worm shaft 4b of the speed reducer unit 4 is operated to rotationally displace the control shaft 13, and for example, as shown in FIG. Set to any lift position on the high valve lift side which is an angle. The camshaft 17 is rotated at the lift position at an arbitrary angle, and the valve lift height output from the intake rocker arm 22 is measured by the lift sensor 40. That is, when the camshaft 17 rotates, the cam displacement of the intake cam 17a is transmitted to the swing cam 25 via the center rocker arm 27 and swings the intake rocker arm 22. The lift sensor 40 follows the oscillating displacement of the intake rocker arm 22 and moves in the vertical direction (reciprocating direction), and measures the valve lift amount shown in FIG. 5 output from each intake rocker arm 22 with reference to the cam rotation angle. Record (dashed line). Here, the case where the maximum valve lift height is measured is taken as an example. When the measurement is completed, the inter-cylinder variation adjusting screw 35 of each cylinder is operated with an adjusting tool 19a such as a driver so that the average of the maximum valve lift height between the cylinders is within a predetermined tolerance. This completes the adjustment on the high valve lift side (solid line).

When the adjustment of the valve lift height is completed, the control shaft 13 is then rotated and displaced in the opposite low valve lift direction as shown by the arrow α in FIG. 3, and the control shaft 13 is moved as shown in FIG. Then, the control shaft 13 is positioned at an angle at which a predetermined low valve lift amount, for example, the average of the maximum valve lift height is a constant low valve lift amount.
Thereafter, the camshaft 17 is rotated and the lift sensor 40 measures the maximum valve lift amount output from each intake rocker arm 22 at the lift position, that is, the maximum valve lift height. It is confirmed whether or not the difference between the measured maximum valve lift heights falls within the predetermined tolerance of the low valve lift position.

  At this time, as shown by the solid line in FIG. 6, the variable valve assembly 1 is determined that the variation between the cylinders has been adjusted if it falls within the specified tolerance. That is, the variable valve system assembly 1 requires a higher accuracy at the low valve lift position than at the high valve lift position because the difference in the amount of air drawn into the engine appears as a difference in engine characteristics. In the variable valve mechanism 19 using the swing cam 25, the swing cam 25 is used as a valve lift when the swing cam 25 slightly enters the lift section from the base circle section at the low valve lift position. Is small. That is, even if the position of the swing cam 25 is adjusted by the adjustment screw 35 and a lift change is applied, the amount of lift displacement is small, so the adjustment sensitivity is low. However, at the high valve lift position, the swing cam is used as a valve lift when it enters the lift section largely from the base circle section. Therefore, the lift section has a large lift displacement, and the position of the swing cam 25 is adjusted by the adjusting screw 35. When a lift change is applied after adjustment, the amount of lift displacement increases and adjustment sensitivity is high. Therefore, in consideration of this characteristic, the valve lift height is adjusted at a point on the high valve lift side where the adjustment sensitivity is high, and then, instead of the lift position of a certain low valve lift amount that requires accuracy, FIG. As shown by the solid line, if it is confirmed that each valve lift height at the lift position is within the specified tolerance at the predetermined lift position, the valve lift height at a point where high valve lift accuracy is not required. Even if it is replaced with a fixed low valve lift point where adjustment accuracy is required, the variation in the range is within a minute tolerance. That is, it is determined that the adjustment of the variation between cylinders has been completed. If the adjustment is finalized, the cylinder-to-cylinder variation adjusting screw 35 that has been adjusted is fixed by a fixing nut 35 a that is screwed into the adjusting screw 35. If the specified tolerance is exceeded as indicated by the broken line in FIG. 6, adjustment of the variation between cylinders is performed again. Or fine adjustments may be made on the low lift side.

In addition, by measuring the lift of the cam rotation angle, it is possible not only to set the measurement standard as the maximum lift amount but also to make adjustments by comparing the valve lift at the specified cam rotation angle and the integrated value of the valve lift as a whole. In this case, the cylinder variation adjustment accuracy can be further increased.
Further, when the variable mechanism 19 is provided for each valve, if there is a difference in valve lift within the same cylinder, the same adjustment as the inter-cylinder variation adjustment is performed.

Furthermore, when the width that can be adjusted greatly exceeds, it is easily determined that the component is defective, and it is possible to identify the defective component depending on how the measured values are shifted during adjustment.
When the adjustment jig 40 is used as described above, the cylinder variation of the variable valve assembly 1 can be easily adjusted. That is, the variable valve assembly 1 has a structure including the camshaft 17 serving as the cam displacement input portion and the intake rocker arm 22 serving as the valve drive force output portion. Unlike the assembly in which only the rocker arm mechanism described above is assembled, the variable valve assembly 1 itself can adjust the variation between cylinders. In consideration of this characteristic, the adjustment operation for the variation between cylinders is performed by using a dedicated adjustment jig 40 that reproduces the assembly equivalent to the cylinder head, not the cylinder head. The troublesome setup work which secures the place which sets a sensor like time, or considers the system which measures is unnecessary. Therefore, the cylinder variation can be easily adjusted.

Moreover, since the lift sensor 45 has a structure in which the detection element 48 detects the movement of the advance / retreat member 46 that is displaced like an intake valve, it can be expected to measure the valve lift amount with a simple structure and high accuracy. Highly accurate cylinder variation adjustment is possible.
In addition, by managing the measurement values, it is possible to easily identify a product defect and increase productivity. Furthermore, productivity is further improved by feeding back the information to correction at the time of manufacturing the child parts.

  Note that the present invention is not limited to one embodiment, and various modifications may be made without departing from the spirit of the present invention. For example, in one embodiment, a variable valve assembly having a structure in which a swing cam is provided between a camshaft and an intake rocker arm is described. However, the present invention is not limited to this, and a variable valve assembly having another structure may be used. In one embodiment, a lift sensor using an advancing / retreating member has been described, but other structures may be used. Further, in one embodiment, the cylinder variation of the variable valve assembly is adjusted by a method of adjusting at the high valve lift position and confirming the adjustment at the low valve lift position. Other methods may be used.

1 Variable valve assembly 17 Camshaft 17a Intake cam (cam)
22 Intake rocker arm (valve drive member)
40 Cylinder variation adjustment jig 40a body (jig body)
45 Lift sensor 46 Advancement / retraction member (displacement member)
48 Detection element (detection unit)

Claims (3)

A camshaft including an intake cam; a valve drive member for each cylinder that drives a valve; and a swing cam that transmits a displacement of the intake cam to the valve drive member. A cylinder variation adjustment jig for adjusting variation among cylinders of the variable valve assembly, which is used in a variable valve assembly assembled so that the cam displacement is varied by the advancement and retraction of the adjustment screw and output from the valve drive member. There,
A jig body for mounting the variable valve assembly in which the protruding amount of the adjusting screw is uniformly matched for each cylinder;
A lift sensor provided on the jig body,
The lift sensor is provided corresponding to each position of the valve drive member when the variable valve assembly is mounted on the jig body, and is adjusted at a lift position on the high valve lift side where adjustment sensitivity is high. Cylinder variation adjustment characterized by measuring a valve lift amount output from the valve drive member in an adjustment operation performed by the variable valve assembly that performs adjustment at a lift position on the low valve lift side having low adjustment sensitivity. jig. The valve driving member has a screw portion that comes into contact with the valve at a tip portion thereof,
In the jig body, the variable valve assembly in which the protruding amount of the screw part from the tip part of the valve driving member is uniformly matched for each cylinder is mounted,
The lift sensor, according to claim 1, characterized in that provided corresponding to each position of the screw portion of the valve driving member when obtained by mounting the variable valve assembly to the fixture body Cylinder variation adjustment jig. The lift sensor
A displacement member that displaces following the movement of the valve drive member;
Cylinder variation adjustment jig according to claim 1 or claim 2, characterized in that it is configured to have a detection unit that detects a displacement amount of the displacement member.

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