CN113756903B

CN113756903B - Holding device for a camshaft

Info

Publication number: CN113756903B
Application number: CN202010499811.6A
Authority: CN
Inventors: 迟晓梅
Original assignee: BMW Brilliance Automotive Ltd
Current assignee: BMW Brilliance Automotive Ltd
Priority date: 2020-06-04
Filing date: 2020-06-04
Publication date: 2022-10-04
Anticipated expiration: 2040-06-04
Also published as: CN113756903A

Abstract

The present disclosure relates to a retaining device (200) for a camshaft (110) mounted on a cylinder head (100) of an engine of a vehicle, characterized in that the retaining device (200) comprises: the fixing mechanism (210) is used for fixing the holding device (200) on the cylinder cover (100) and the pressing mechanism (220) is used for pressing a bearing cover (120) of the camshaft (110), the fixing mechanism (210) comprises a supporting plate (211) used for bearing the pressing mechanism (220), a positioning unit (212) used for pre-positioning the holding device (200) on a lateral air inlet surface of the cylinder cover (100) and a fastening unit (213) used for fastening the holding device (200) on a lateral air outlet surface of the cylinder cover (100), and the pressing mechanism (220) comprises an elongated block (221) which can move along the vertical direction and is provided with a plurality of pressing pins and a transmission unit which can enable the elongated block (221) to move along the vertical direction and connects the supporting plate with the elongated block (221).

Description

Holding device for a camshaft

Technical Field

The present disclosure relates to a cylinder head of a vehicle engine, and more particularly, to a retainer device for a camshaft mounted on the cylinder head.

Background

In a vehicle, a cylinder head is located above a cylinder block of an engine, mainly for sealing an upper portion of a cylinder, and constitutes a combustion chamber together with a piston, the cylinder, and the like. When the cylinder cover works, air is sucked into the cylinder, then the combustible mixed gas is ignited by the spark plug to drive the piston to do work, and finally the waste gas is discharged from the exhaust pipe.

The valve train of the engine is divided into two parts of a valve group and a valve transmission group. The core of the valve group is a valve and a valve spring. The valve spring is used for driving the valve to close (opening is realized by a cam on a camshaft), and the elastic force of the valve spring determines the closing speed of the valve, so that some engines are provided with two valve springs on each valve to ensure the elastic force. The valve transmission set drives the valves to open by utilizing the power of the crankshaft, and ensures the opening and closing actions of the valves to be synchronous with the crank-connecting rod mechanism. The timing chain (belt) mainly comprises a timing chain (belt), a timing chain (belt) wheel, a cam shaft, a rocker arm, a tappet and the like.

At present, passenger car engines are basically arranged by adopting an overhead camshaft (OHC), the camshaft is positioned on a cylinder cover, and a crankshaft drives the camshaft to rotate through a timing chain (belt). When installing a timing chain or belt, the crankshaft and camshaft must first be properly timing-marked to ensure the correct timing relationship. The camshaft is a shaft provided with cams, the cams are usually integrated with the shaft, and the cams have specific position relations, and the position relations determine the working sequence and the valve timing of each cylinder of the engine. Meanwhile, the shape of the cam determines the opening time and lift (opening amplitude) of the valve. Rocker arms and lifters are the end drive members of the valve train, typically pushing the valves directly.

When the camshaft is mounted on the cylinder head, after the cylinder head is assembled, it is checked by an automatic device to check whether the camshaft is rotated well. If the camshaft becomes jammed or rotates improperly, the rework process should be entered. In this case, a plurality of bearing caps should be removed.

Since the thrust clearance of the camshaft is small, the camshaft must be held horizontally and removed vertically. If the camshaft cannot be kept horizontal, the cylinder head may crack or break against the thrust of the shaft, causing deformation or breakage of the camshaft. Moreover, because the valve springs are pre-tensioned, removing the bearing caps from either side presents a safety hazard to the operator. Here, the valve spring is directly released, and thus the operator needs a tool capable of pressing the camshaft for rework. This work can be done smoothly.

Disclosure of Invention

In view of the above, the present disclosure provides a holding device for a camshaft, with which the above-mentioned safety hazards of the rework process can be eliminated, among other things.

According to the concept of the present disclosure, there is provided a holding device for a camshaft mounted on a cylinder head of an engine of a vehicle, characterized by comprising: a fixing mechanism for fixing the holding device on the cylinder head and a pressing mechanism for pressing a bearing cap of the camshaft; the fixing mechanism comprises a supporting plate for carrying the pressing mechanism, a positioning unit for pre-positioning the holding device on the lateral air inlet surface of the cylinder cover and a fastening unit for fastening the holding device on the lateral air outlet surface of the cylinder cover; the pressing mechanism comprises an elongated block body which can move in the vertical direction and is provided with a plurality of pressing pins and a transmission unit which can enable the elongated block body to move in the vertical direction and connects the supporting plate with the elongated block body.

Thus, with the holding device according to the present disclosure, it is possible to hold the position of the bearing cap by its pressing mechanism without being changed by the valve spring. Therefore, the operator has no safety hazard when completing the disassembling work. Furthermore, when removing the bearing caps, the operator does not have to remove the bearing bolts from the bearing caps in a certain order, but can remove them in any order. In addition, the entire rework process may be done by only one operator, as no other operator is required to cooperate with the compression bearing cap to prevent accidental lifting of the camshaft.

Preferably, the number and spacing of the pressure pins substantially correspond to the number and spacing of the bearing caps, and the elongated block is positioned directly above the camshaft when the retaining device has been mounted on the cylinder head, and the pressure pins are each located above a respective bearing cap. In this way, all the bearing caps can be pressed, so that the pressing force is distributed more uniformly.

The drive unit is preferably designed as an eccentric drive unit, wherein the positioning wheel designed as an eccentric can be rotated by a movement of a pressing handle on a splined shaft fixedly connected thereto, so that the elongated block can be moved in the vertical direction. In this way, a motion conversion can be simply achieved, so that the movement in the horizontal direction is used to move the elongated block in the vertical direction. Moreover, the eccentric wheel can make the structure more compact and make the movement of the strip-shaped block body more gentle.

Preferably, the positioning wheel is able to drive the elongated block in a vertical direction via a compression column, and the compression column extends through a hole provided in the support plate. The vertical height of the holding device is thereby increased in a simple manner.

Preferably, the support plate is rectangular, wherein the length of the support plate parallel to the longitudinal direction of the camshaft is less than or equal to the longitudinal length of the camshaft, but at least greater than half the longitudinal length of the camshaft, and the width of the support plate perpendicular to the longitudinal direction of the camshaft is greater than or equal to the width of the cylinder head. However, it is conceivable that the support plate can be designed in any shape, as long as it can connect the lateral positioning unit and the fastening unit and can carry the hold-down mechanism.

Preferably, the positioning unit includes at least two legs, each leg extending vertically downward from the support plate at a first side of the support plate parallel to the longitudinal direction of the camshaft and being extendable at least to a corresponding one of the bolt mounting holes of the cylinder head, a locking leg provided on a lower end portion of each leg near the bolt mounting hole, the locking leg being insertable into the corresponding bolt mounting hole, and a positioning rod provided on an upper end portion of each leg, the locking leg being rotatable so as to be inserted into the corresponding bolt mounting hole by operating the positioning rod. In this way, a prepositioning of the holding device can be achieved in a simple manner.

Preferably, the fastening unit includes a side support plate extending vertically downward from the support plate at a second side of the support plate opposite to a first side thereof, a cross bar extending from the side support plate at a distance from a lower end portion of the side support plate parallel to the support plate toward the first side of the support plate, a locking pin provided in a guide hole at the lower end portion of the side support plate, the locking pin being movable toward the first side of the support plate by operating a locking pin handle and thereby being pressed against the lateral exhaust surface of the cylinder head. In this way, the fastening of the retaining device on the cylinder head can be achieved simply.

Preferably, the locking pin handle is connected to the locking pin by a link mechanism so as to enable the locking pin to move toward the first side of the support plate. The locking movement of the locking pin is thereby simply achieved.

Preferably, the holding device further comprises a guide mechanism for guiding the holding device in a vertical direction. In this connection, the guide means is preferably designed as a guide plate which is located on one side of the support plate perpendicular to the longitudinal direction of the camshaft and extends vertically downwards. In this way, the fixing of the retaining device on the cylinder head can be made more smooth and accurate.

Drawings

In order to make the aforementioned objects, features and advantages of the present disclosure more comprehensible, embodiments accompanying the present disclosure are described in detail below.

FIG. 1 is a schematic view of a cylinder head with a camshaft mounted thereto;

FIG. 2A is a perspective view of a retaining device for a camshaft according to an embodiment of the present disclosure;

FIG. 2B is another perspective view of a retaining device for a camshaft according to an embodiment of the present disclosure;

FIG. 3A is a schematic view of a camshaft compressed using a retaining device according to the present disclosure;

fig. 3B is an enlarged view of a circled portion S in fig. 3A.

Detailed Description

In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. The invention can be implemented in a number of ways different from those described herein and similar generalizations can be made by those skilled in the art without departing from the spirit of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

The expression "and/or" is used herein in the sense of including at least one of the components listed before and after the expression. Also, the expression "connected" is used in a sense that it includes a direct connection with another component or an indirect connection through another component. The singular forms herein also include the plural unless specifically mentioned in the context of a phrase. Also, as used herein, reference to "a component, step, operation, and element that" includes "or" comprises "means that at least one other component, step, operation, and element is present or added.

Fig. 1 is a schematic view of a cylinder head 100 mounted with a camshaft 110. As shown in fig. 1, the camshaft 110 may be secured to the cylinder head 100 by a plurality of bearing caps 120. When the cylinder head 100 has been assembled, the camshaft 110 preloads the valve spring 140 via the rocker arm 130.

As described above, after the assembly of the cylinder head 100 is completed, the inspection may be performed by an automatic device to check whether the camshaft 100 is rotated well. If the camshaft 100 is jammed or rotates improperly, a rework process should be entered. In this case, the bearing cap 120 should be removed. Because the valve spring 140 is pre-tensioned, removing the bearing cap 120 from either side creates a safety hazard to the operator if the valve spring 140 is released directly.

In view of this, the present disclosure proposes a retention device 200 for a camshaft 100. Fig. 2A and 2B illustrate perspective views from different angles of a retaining device 200 for a camshaft 100 according to an embodiment of the present disclosure.

The retainer device 200 according to this embodiment includes a fixing mechanism 210 for fixing the retainer device 200 to the cylinder head 100.

The fixing mechanism 210 includes a support plate 211 for carrying a pressing mechanism 220 to be described later, a positioning unit 212 for pre-positioning the holder device 200 on the cylinder head 100, and a fastening unit 213 for fastening the holder device 200 on the cylinder head 100.

The positioning unit 212 is disposed at a first side of the support plate 211 in the length direction. The first side is located above the intake face of the cylinder head 100 when the retainer device 200 has been mounted on the cylinder head 100. The positioning unit 212 comprises at least two legs 2121, and in this embodiment, comprises exactly two legs 2121. Each leg 2121 extends vertically downward from the support plate 211 at a first side of the support plate 211 and is capable of extending to at least a respective one of the intake face bolt mounting holes of the cylinder head 100. A locking foot 2122 is provided on a lower end of each leg 2121 near the bolt mounting hole, and is insertable into the corresponding bolt mounting hole. A locating rod 2123 is provided on the upper end of each leg 2121 and is mechanically operatively connected to the locking foot 2122 via the leg 2121. By operating the positioning rod 2123, the locking legs 2122 can be rotated so as to be inserted into the corresponding bolt mounting holes.

The fastening unit 213 is disposed at a second side of the support plate 211 opposite to the first side thereof. The second side is located above the exhaust surface of the cylinder head 100 when the retainer device 200 has been mounted on the cylinder head 100. The fastening unit 213 includes side plates 2131, a cross bar 2132, a locking pin 2133, and a locking pin handle 2134.

The side straps 2131 extend vertically downward from the support plate 211 at a second side edge of the support plate 211. The cross bar 2132 extends from the side branch plate 2131 parallel to the support plate 211 towards a first side of the support plate at a distance from the lower end of the side branch plate 2131. Therefore, the cross bar 2132 may abut against the upwardly facing narrow side of the cylinder head casing side plate of the cylinder head 100 when the retainer device 200 has been mounted on the cylinder head 100.

The locking pin 2133 is provided in a guide hole at the lower end of the side support plate 2131. The locking pin handle 2134 is mechanically operatively connected to the locking pin 2133, such as by a linkage mechanism. By operating the clamp pin handle 2134, the clamp pin 2133 can be moved toward the first side of the support plate 211 and can be pressed against the exhaust surface of the cylinder head 100.

The holding device 200 according to this embodiment further includes a pressing mechanism 220 for pressing the bearing cap 120 of the camshaft 110. The compacting mechanism 220 includes an elongated block 221. A plurality of compression pins 2210 directed vertically downward are mounted on the elongated block 221. The number and spacing of the compression pins 2210 substantially corresponds to the number and spacing of the bearing caps. When the retainer 200 has been mounted on the cylinder head 100, the elongated blocks 221 are positioned directly above the camshaft, and the compression pins 2210 mounted on the elongated blocks 221 are located above the corresponding bearing caps, respectively.

As shown in fig. 2B, in order to enable the elongated block 221 to move in the vertical direction a, the pressing mechanism 220 further includes a transmission unit. In this embodiment, the gear unit is designed as an eccentric gear unit and can comprise a positioning wheel 222, a spline shaft 223 and a pressing handle 224. The pressing handle 224 is fixedly connected with the spline shaft 223. The spline shaft 223 is fixedly connected to a positioning wheel 222 in the form of an eccentric wheel.

The positioning wheel 222 can be rotated by moving the compression handle 224 in the operating direction B. Due to the rotation of the positioning wheel 222, which is designed as an eccentric, the pressing cylinder 226 located therebelow can be moved in the vertical direction. The pressing column 226 can drive the elongated block 221 to move along the vertical direction a.

In addition, in order to move the pressing column more stably, the pressing column 226 extends through a hole provided on the support plate 211, and a bushing 225 may be provided in the hole for the pressing column.

The holding fixture 200 may also optionally include a guide mechanism that guides the holding fixture 200 in the vertical direction. In the present embodiment, the guide mechanism is configured as a guide plate 230 that is located on one side edge of the support plate 211 in the width direction and extends vertically downward.

Fig. 3A is a schematic view of compressing the camshaft 110 using the retainer device 200 according to the present disclosure, and fig. 3B is an enlarged view of a circled portion S in fig. 3A.

As can be seen from fig. 3A, the holding fixture 200 is fixed to the cylinder head 100 with its fixing mechanism 210, and the compression pin 2210 of the compression mechanism 220 of the holding fixture 200 is compressed against the bearing cap 120 of the camshaft 110. As is apparent in particular from fig. 3B, the compression pin 2210 mounted on the elongated block 221 is compressed against a point in the middle of the two bearing bolts on the bearing cap 120 of the camshaft 110.

In operating the holding device 200 according to the present disclosure, the positioning unit 212 of the fixing mechanism 210 is first positioned in the bolt mounting hole on the intake face of the cylinder head 100. Then, the clamp pins 2133 of the fastening units 213 of the fixing mechanism 210 are pressed against the exhaust surface of the cylinder head 100. Thereby positioning the elongated block 221 of the hold-down mechanism 220 over the camshaft 110. By operating the pressing handle 224, the pressing pin 2210 mounted on the elongated block 221 is pressed against a point between two bearing bolts of the bearing cap 120 of the camshaft 110. Whereby the retaining device 200 will maintain the position of each bearing cap 120. The bearing bolts on the bearing cap can then be removed using a tool. After all bearing bolts are removed, the elongated block 221 of the hold-down mechanism 220 is raised. Whereby the bearing cap can be smoothly detached.

The features disclosed in the present document can be essential for the implementation of the embodiments in terms of different embodiments and can be implemented both individually and in any combination. The invention is not limited to the embodiments shown but comprises or extends to all technical equivalents that may fall within the scope and spirit of the appended claims.

Claims

1. A holding device (200) for a camshaft (110) mounted on a cylinder head (100) of an engine of a vehicle, characterized in that the holding device (200) comprises: a fixing mechanism (210) for fixing the holding device (200) to the cylinder head (100) and a pressing mechanism (220) for pressing the bearing cap (120) of the camshaft (110),

the fixing mechanism (210) comprises a supporting plate (211) for carrying the pressing mechanism (220), a positioning unit (212) for pre-positioning the holding device (200) on the lateral air inlet surface of the cylinder head (100), and a fastening unit (213) for fastening the holding device (200) on the lateral air outlet surface of the cylinder head (100),

the pressing mechanism (220) comprises an elongated block (221) with a plurality of pressing pins (2210) capable of moving in the vertical direction (A) and a transmission unit capable of moving the elongated block (221) in the vertical direction (A) and connecting the support plate (211) with the elongated block (221).

2. The holding arrangement according to claim 1, characterized in that the number and spacing of the compression pins (2210) substantially correspond to the number and spacing of the bearing caps (120), and that the elongated blocks (221) are positioned directly above the camshaft and the compression pins (2210) are located above the respective bearing caps (120) when the holding arrangement (200) has been mounted on the cylinder head (100).

3. Holding device according to claim 1 or 2, characterized in that the transmission unit is designed as an eccentric transmission unit, wherein the positioning wheel (222) designed as an eccentric can be rotated by the movement of a pressing handle (224) on a splined shaft (223) fixedly connected thereto, so that the elongated block (221) can be moved in the vertical direction (a).

4. A holding device according to claim 3, characterized in that the positioning wheel (222) is capable of moving the elongated block (221) in the vertical direction (a) via a pressing column (226) extending through a hole provided in the support plate (211).

5. The holding device according to claim 1 or 2, characterized in that the support plate (211) is configured rectangular, wherein the length of the support plate (211) parallel to the longitudinal direction of the camshaft (110) is less than or equal to the longitudinal length of the camshaft (110) but at least greater than half the longitudinal length of the camshaft (110), and the width of the support plate (211) perpendicular to the longitudinal direction of the camshaft (110) is greater than or equal to the width of the cylinder head (100).

6. The holder according to claim 1 or 2, characterized in that the positioning unit (212) comprises at least two legs (2121), each leg (2121) extending vertically downward from the support plate (211) at a first side of the support plate (211) parallel to the longitudinal direction of the camshaft (110) and being capable of extending at least to a corresponding one of the bolt mounting holes of the cylinder head (100), a locking leg (2122) being provided on a lower end portion of each leg (2121) near the bolt mounting hole, the locking leg being capable of being inserted into the corresponding bolt mounting hole, and a positioning rod (2123) being provided on an upper end portion of each leg (2121), the locking leg (2122) being capable of being rotated to be inserted into the corresponding bolt mounting hole by operating the positioning rod.

7. The holding device according to claim 6, wherein the fastening unit (213) includes a side support plate (2131) vertically extending downward from the support plate (211) at a second side of the support plate (211) opposite to the first side thereof, a cross bar (2132) extending from the side support plate (2131) toward the first side of the support plate parallel to the support plate (211) at a distance from a lower end portion of the side support plate (2131), a locking pin (2133) provided in a guide hole at the lower end portion of the side support plate (2131), and the locking pin (2133) being movable toward the first side of the support plate (211) by operating a locking pin handle (2134) and thereby pressing the locking pin (2133) against the side exhaust surface of the cylinder head (100).

8. The holding device according to claim 7, wherein the locking pin handle (2134) is connected to the locking pin (2133) by a linkage mechanism, thereby enabling the locking pin (2133) to move towards the first side of the support plate (211).

9. Holding device according to claim 1 or 2, characterized in that the holding device (200) further comprises a guide mechanism for guiding the holding device (200) in a vertical direction.

10. The holding device according to claim 9, characterized in that the guide means are formed as a guide plate (230) which is located on one side of the support plate (211) perpendicular to the longitudinal direction of the camshaft (110) and extends vertically downwards.