CN202325721U - Cam shaft for engine - Google Patents

Abstract

The utility model discloses an engine camshaft, which comprises a front end connected to a VVT rotor, a tail end opposite to the front end, and a camshaft body located between the front end and the tail end. The camshaft body is sequentially There are a front thrust ring, a first journal, a first axle bottom, a rear thrust ring, and a first cam. The front thrust ring is integrally connected with the front end. The front end of the shaft is provided with positioning pins and four oil holes extending axially along the camshaft. The other ends of the four oil holes are respectively opened in one of the ring grooves. The pins are distributed along the circumference of the camshaft. Increase the diameter of the first journal of the camshaft to realize the opening of the VVT oil passage on the camshaft. The oil holes at the front end of the camshaft are arranged in an isosceles trapezoidal form, so that the rotor has more space for opening the oil passage, which can be matched with the vane type. VVT is used, and the amount of modification to other components such as the cylinder head is reduced.

Description

an engine camshaft

technical field

The utility model relates to a camshaft, in particular to an engine camshaft.

Background technique

VVT (Variable Valve Timing) is the variable valve timing technology. Through the equipped control and execution system, the phase of the engine cam is adjusted, so that the valve opening and closing time changes with the engine speed to improve the charging efficiency. , to increase engine power. The principle of engine variable valve timing (VVT, Variable Valve Timing) technology is to adjust the amount of intake (exhaust), valve opening and closing time, and angle according to the operating conditions of the engine, so as to achieve the best air intake and improve combustion efficiency.

When the engine is upgraded to improve the variable valve timing technology, it is necessary to add internal structures or parts to the cylinder head and other components. Because the main parts such as the cylinder head in the engine are not suitable for changes or only a few changes can be made, otherwise the engine needs to be modified. A comprehensive structural adjustment will lead to higher transformation costs and relatively higher risks. In order to meet the requirements of unchanged parts such as cylinder head, structural modification of the camshaft is required. In addition, components such as the cylinder head also have certain restrictions on the size of the connecting part of the camshaft and the bearing, that is, the diameter of the corresponding part of the camshaft is limited.

Contents of the invention

Aiming at the deficiencies of the prior art, the technical problem to be solved by the utility model is to provide an engine camshaft that can be used in conjunction with a vane-type VVT and can reduce the modification of the cylinder head.

In order to solve the above technical problems, the technical solution adopted by the utility model is: an engine camshaft, which is arranged in the engine camshaft cover and connected with the VVT rotor, the engine camshaft includes a front end connected with the VVT rotor, and The tail end opposite to the front end, the camshaft body between the front end and the tail end, the camshaft body is sequentially provided with a front thrust ring, a first journal, a first shaft bottom, a rear The thrust ring and the first cam, the front thrust ring is integrally connected with the front end, the first journal is provided with two ring grooves, the front end of the camshaft is provided with positioning pins, four edge The oil holes extending axially on the camshaft, the other ends of the four oil holes are respectively opened in one of the annular grooves, the four oil holes are arranged in an isosceles trapezoidal shape and distributed along the circumference of the camshaft with the positioning pins.

As an improvement of the above solution, the front end surface of the camshaft is further provided with a central oil drain hole extending axially along the camshaft, and the other end of the central oil drain hole opens to the top ring surface of the rear thrust ring.

As an improvement of the above solution, the side of the front thrust ring connected to the first journal is a front thrust surface, and the side of the rear thrust ring connected to the first shaft bottom is a rear thrust surface.

As an improvement of the above solution, the tail end has a wrench position with a regular hexagonal section.

As an improvement of the above solution, the tail end is provided with an inline tail groove along the radial direction of the camshaft.

As an improvement to the above solution, the camshaft body is provided with an annular boss.

As an improvement to the above solution, the camshaft body is provided with four sets of cams, and shoulders are reserved on both sides of the cams.

The beneficial effect of the utility model is that: the diameter of the first journal of the camshaft is increased, and two annular grooves are provided, that is, the lubricating oil path is arranged on the journal, and the bearing cap is avoided from opening an annular groove to provide lubrication, which can reduce the Changes to the cylinder head. A VVT oil passage is set at the front end of the camshaft, that is, four oil holes are opened on the front end, and two oil holes communicate with a ring groove through a connecting hole opened in the radial direction, so that the VVT oil passage is opened on the camshaft. Therefore, the front end of the camshaft integrates VVT oil holes, ring grooves and positioning pins, and the four oil holes are arranged in an isosceles trapezoidal form, that is, the openings of the four VVT oil holes are distributed unevenly but symmetrically on the front surface of the camshaft. This distribution form is beneficial to the configuration of the oil passage in the VVT rotor connected to it, and the position of the interface corresponding to the rotor at the opening is more dispersed, so that the rotor has more space for opening the oil passage, thereby reducing the design difficulty of the VVT rotor oil passage, thereby This camshaft can be used with vane VVT. By setting the oil passage on the camshaft, the amount of modification to other components such as the cylinder head can also be reduced.

Description of drawings

Fig. 1 is a three-dimensional structure diagram of an embodiment of an engine camshaft of the present invention.

Fig. 2 is a schematic perspective view of another embodiment of the engine camshaft.

Fig. 3 is a schematic diagram of the partial structure of the front end in the embodiment of the engine camshaft.

Fig. 4 is a sectional structure diagram of the front end of the engine camshaft.

Fig. 5 is another cross-sectional structural schematic diagram of the front end of the engine camshaft.

Fig. 6 is a schematic diagram of the front end structure of the engine camshaft.

Fig. 7 is a structural schematic diagram of a cam in the embodiment.

FIG. 8 is a partially enlarged view of area A in FIG. 7 .

Fig. 9 is a structural schematic diagram of an assembly embodiment of an engine camshaft.

Detailed ways

The specific embodiment of the utility model will be further described below in conjunction with the accompanying drawings.

As shown in Figures 1 to 6, an engine camshaft of the present invention is arranged in the engine camshaft cover 80 and connected with the VVT rotor, the engine camshaft includes a front end 30 connected with the VVT rotor, and the The tail end portion 50 opposite to the front end portion 30, the camshaft body 10 between the front end portion 30 and the tail end portion 50, the camshaft body 10 is provided with a front thrust ring 15, a first journal 18, The first shaft bottom 22, the rear thrust ring 25, and the first cam 12, the front thrust ring 15 is integrally connected with the front end portion 30, the first journal 18 is provided with two ring grooves 20, the The front end surface 32 corresponding to the front end of the camshaft is provided with a positioning pin 33 and four oil holes 35 extending axially along the camshaft. The other ends of the four oil holes 35 are respectively opened in one of the ring grooves 20. The oil holes 35 are arranged in an isosceles trapezoidal shape and are distributed with the positioning pins 33 along the circumferential direction of the camshaft.

Increase the diameter of the first journal 18 of the camshaft, and open two ring grooves 20, that is, set the lubricating oil path on the first journal, avoid opening the ring groove 20 in the bearing cover to provide lubrication, and reduce the impact on the cylinder head. changes. A VVT oil passage is set at the front end of the camshaft, that is, four oil holes 35 are opened on the front end surface, and two oil holes 35 communicate with a ring groove 20 through a connecting hole opened in the radial direction, so as to realize the opening of a VVT oil passage on the camshaft . Therefore, the front end of the camshaft integrates a VVT oil hole 35, an annular groove 20 and a positioning pin 33, and is connected with the VVT rotor through these components. The four oil holes 35 are arranged in an isosceles trapezoidal form, that is, the openings of the four VVT oil holes are distributed unevenly but symmetrically on the front face of the camshaft. This distribution form is beneficial to the internal oil passage of the VVT rotor connected to it. Configuration, the position of the interface corresponding to the rotor at the opening is more scattered, so that the rotor has more space for oil passage, thereby reducing the design difficulty of the VVT rotor oil passage, so that the camshaft can be used with the vane VVT. Enlarging the diameter of the first journal 18 allows the VVT oil circuit to be directly processed on the camshaft (processing the ring groove on the outer peripheral surface of the cylinder) without processing it on the camshaft cover (processing the groove in the inner hole), thereby reducing the Difficulty in processing reduces the cost, thereby reducing the amount of changes to other components such as the cylinder head by setting the oil passage on the camshaft.

More preferably, the front end surface 32 corresponding to the front end portion 30 of the camshaft is also provided with a central oil drain hole 36 extending axially along the camshaft, and the other end of the central oil drain hole 36 opens to the rear thrust ring 25, the section connecting the central oil drain hole 36 and the front end surface 32 is set as a threaded hole, which is used to connect the hollow VVT bolts, and returns the oil leaked inside the VVT to the cylinder head oil chamber through the camshaft, thereby The amount of modification to other components such as the cylinder head can be reduced.

More preferably, the side of the front thrust ring 15 connected to the first journal 18 is the front thrust surface 16 , and the side of the rear thrust ring 25 connected to the first shaft bottom 22 is the rear thrust surface 26 . The asymmetrically arranged thrust surface is arranged at a section near the front end of the camshaft, which makes the whole camshaft appear simple and compact, reduces manufacturing cost, is easy to process, and better matches the design of the cylinder head. The front thrust surface 16 of the utility model is located on the front side of the first journal, and the rear thrust surface 26 is located on the rear side of the first shaft bottom 22. This structure can make full use of the corresponding stop on the camshaft front bearing cover. The thrust surface controls the axial movement of the camshaft, which saves space and simplifies the structure of the thrust surface.

More preferably, the tail end portion 50 has a wrench position 56 with a regular hexagonal cross section. The hexagonal wrench position 56 facilitates the use of a wrench to rotate the camshaft during assembly, which facilitates the adjustment and installation of the camshaft, and facilitates timing and positioning.

More preferably, as shown in FIG. 9 , the tail end portion 50 is provided with an in-line tail groove 52 along the radial direction of the camshaft. When the timing is installed, the tail groove 52 can be embedded in the rigid plate 82, and the extended part of the plate 82 is in contact with the cylinder head 80 to ensure the level of the tail groove 52, so as to realize the orientation and positioning of the camshaft, so as to install the VVT and the timing belt . Both the tail groove 52 and the wrench position 56 are set at the tail end 50, that is, the distance between the two is very close, so that the assembler can easily perform single-person operation during the assembly work, which reduces the difficulty of assembly and saves labor costs .

More preferably, the camshaft body 10 is provided with an annular boss 58 . The annular boss 58 is set as a distinguishing boss, that is, as a structure for distinguishing the intake camshaft and the exhaust camshaft, so that the intake camshaft and the exhaust camshaft can share the same blank, reducing the mold cost. When distinguishing, a machining method can be selected to remove the annular boss 58, thereby distinguishing the intake/exhaust camshaft.

More preferably, as shown in FIG. 7 and FIG. 8 , the camshaft body 10 is provided with four sets of cams 62 , and shoulders 66 are reserved on both sides of the cams 62 . In addition to the conventional chamfer 65, the two sides of the cam 62 are also provided with a shoulder 66 structure, so that when the cam is ground, the number of grinding wheel repairs can be reduced and the life of the tool (grinding wheel) can be improved.

What is disclosed above is only the preferred embodiment of the present utility model, and of course the scope of rights of the present utility model cannot be limited with this. Therefore, the equivalent changes made according to the patent scope of the utility model still belong to the scope covered by the utility model .

Claims (7)

1. engine cam; Be arranged in the engine camshaft cover and and be connected with the VVT rotor; It is characterized in that: said engine cam comprises the front end that is connected with the VVT rotor, the tail end relative with said front end, the camshaft body between said front end and tail end; At the bottom of said camshaft body is provided with preceding thrust ring, first axle journal, first successively, back thrust ring, first cam; Thrust ring is connected with said front end one before said, and said first axle journal is provided with two annular grooves, and the front-end face of said camshaft is provided with locating stud, four along the axially extended oilhole of camshaft; The other end of said four oilholes is opened on one of them annular groove respectively, and said four oilholes are the isosceles trapezoid arrangement and circumferentially distribute along camshaft with said locating stud.

2. engine cam according to claim 1 is characterized in that: the front-end face of said camshaft also is provided with along draining hole, the axially extended center of camshaft, and the other end in draining hole, said center is opened on the apical ring face of said back thrust ring.

3. engine cam according to claim 1 is characterized in that: the side that thrust ring is connected with first axle journal before said is preceding thrust surface, and said back thrust ring is the back thrust surface with the side that is connected at the bottom of first.

4. engine cam according to claim 1 is characterized in that: it is orthohexagonal spanner position that said tail end has the cross section.

5. engine cam according to claim 1 is characterized in that: said tail end radially is provided with the yi word pattern stern notch along camshaft.

6. engine cam according to claim 1 is characterized in that: said camshaft body is provided with annular boss.

7. engine cam according to claim 1 is characterized in that: said camshaft body is provided with four groups of cams, and shoulder is reserved in the both sides of said cam.

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