A kind of cylinder head and overhead camshaft engine
Technical field
The present invention relates to engine art, be specifically related to a kind ofly utilize straight oilhole for the cylinder head of valve rocker fuel feeding and adopt the overhead camshaft engine of this cylinder cap.
Background technique
In the developing of automobile industry process, miniaturization, compactness how to realize motor is the target that the designer constantly pursues always.
In Chinese patent application number: in the patent of invention of 96192117.X, the applying date: 1996-10-16, denomination of invention " rocker arm assembly of internal-combustion engine ", a kind of internal-combustion engine is disclosed, valve rocker is installed on the cylinder head by rocker arm support, and when rocker arm support being installed being fastened on the cylinder cap, need cast out the rocker arm support installation base at cylinder cap.And, in order to provide lubricated to valve rocker, be provided with oil leab at rocker arm support and rocking arm support pads.And in this patent, valve rocker needs push rod to support, and this has limited motor reducing on short transverse.
In Chinese patent application number: in the utility model patent of 201220401277.1, the applying date: 2012-8-14, denomination of invention " overhead camshaft cylinder cap ", further disclose the back oil road of cylinder head to the oil duct of rocker arm support installation base fuel feeding.Because the structure of motor is very compact, for the structures such as water jacket around dodging, back oil road can only be positioned at the below of camshaft fitting seat, and for consideration easy to process, the rocker arm support installation base adopts inclined oil hole of air and back oil road to connect.But inclined oil hole of air has also limited the further miniaturization of motor, has room for improvement.
Summary of the invention
The objective of the invention is to overcome above-mentioned shortcoming, a kind of cylinder head of compact structure is provided, to realize the further miniaturization of motor.
For achieving the above object, the invention provides following technological scheme:
A kind of cylinder head, described cylinder head has end face, air inlet side, exhaust side, front-end face and ear end face, be distributed with camshaft fitting seat and rocker arm support installation base on the described end face, the back oil road that has perforation between described front-end face and the described ear end face, described cylinder head has the first straight oilhole that begins to extend straight down from described rocker arm support installation base and begins the horizontally extending second straight oilhole from described air inlet side, the described first straight oilhole is communicated with the described second straight oilhole, and the described second straight oilhole is communicated with described back oil road.
Preferably, the described second straight oilhole at the opening of described air inlet side by shutoff.
Preferably, the opening of the described second straight oilhole in described air inlet side carries out shutoff by blanking cover.
A kind of overhead camshaft engine comprises: aforesaid cylinder head; Be installed in the camshaft in the described camshaft fitting seat; Be installed in the rocker arm support on the described rocker arm support installation base, it comprises intake rocker Support cushion and exhaust rocker arm Support cushion, described intake rocker Support cushion is connected by bridging portion with described exhaust rocker arm Support cushion, is installed with intake rocker bearing and exhaust rocker arm bearing respectively on described intake rocker Support cushion and the described exhaust rocker arm Support cushion; Intake rocker, the one end has the roller that is subjected to described camshaft actuated, and the other end connects a pair of air intake valve, and middle rotating shaft is fixedly mounted on the described intake rocker bearing; Exhaust rocker arm, the one end has the roller that is subjected to described camshaft actuated, and the other end connects a pair of drain tap, and middle rotating shaft is fixedly mounted on the described exhaust rocker arm bearing; The rotating shaft of described intake rocker and the skew of the shaft parallel of described exhaust rocker arm are come.
Preferably, has the oil duct that is communicated with the described first straight oilhole on the described rocker arm support to provide lubricating oil to described intake rocker and described exhaust rocker arm.
Preferably, the rotating shaft of described roller is made by the lead brass wire rod.
Preferably, have oil groove in the rotating shaft of described roller.
Preferably, have two pairs of described intake rocker Support cushions and described exhaust rocker arm Support cushion on each described rocker arm support.
Because the present invention has adopted two mutually perpendicular straight oilholes to replace the general inclined oil hole of air that adopts, therefore the rotating locus of the cam of camshaft can be similar to two straight oilholes tangent, with respect to being similar to tangent comparing with inclined oil hole of air, make camshaft more close rocker arm support installation base on the width between air inlet side and the exhaust side, on short transverse, also can be lowered simultaneously, correspondingly, the size of whole motor can be reduced, realize the compacter layout of motor, be beneficial to the realization miniaturization.
Further, the second straight oilhole carries out shutoff by blanking cover after machining, neither influence the performance of motor, utilizes original shutoff operation to carry out shutoff again, does not need to increase miscellaneous equipment or increases operation.
Further, thereby the roller that the present invention adopts camshaft directly to contact valve rocker drives inlet valve rocker and exhaust valve rocker arm, cancelled push rod, make structure simpler, highly also can be further reduced, and after the skew of the shaft parallel of intake rocker and exhaust rocker arm, can either make the width of motor as far as possible little, be conducive to the inlet and outlet timing again.
Further, the oil duct on the rocker arm support is communicated with the first straight oilhole, can provide lubricated for valve rocker and assembly thereof, improves motor working life.
Further, by the lead brass wire rod make roller rotating shaft, drive oil groove in the rotating shaft of roller, all make between rotating shaft and the roller more wear-resistingly, increase the service life.
Further, two pairs of intake rocker Support cushions and exhaust rocker arm Support cushion are set on the rocker arm support, can further improve installation precision, guarantee air inlet, exhaust synchronism between the adjacent cylinder.
Description of drawings
Next will be described in further detail specific embodiments of the invention by reference to the accompanying drawings, wherein:
Fig. 1 is a kind of plan view of cylinder head of overhead camshaft engine;
Fig. 2 is the stereogram of the motor of embodiments of the invention, and the part assembly on the motor is omitted;
Fig. 3 is the sectional view along the A-A line of Fig. 1, has shown the oil leab structure of prior art;
Fig. 4 is the sectional view along the A-A line of Fig. 1 of similar Fig. 3, has shown the oil leab structure of embodiments of the invention;
Fig. 5 is the structural principle contrast schematic representation of the oil leab structure of the oil leab structure of embodiments of the invention and prior art;
Fig. 6 is the stereogram of the rocker arm support of embodiments of the invention;
Fig. 7 is the explosive view of the valve rocker of embodiments of the invention;
Fig. 8 is the partial top view of Fig. 2.
Last figure mark explanation: end face 1, air inlet side 2, exhaust side 3, front-end face 4, ear end face 5, camshaft fitting seat 6; rocker arm support installation base 7; back oil road 8; inclined oil hole of air 9; the first straight oilhole 10; the second straight oilhole 11; water jacket 12; camshaft 13; rocker arm support 14; intake rocker Support cushion 15; exhaust rocker arm Support cushion 16; bridging portion 17; intake rocker bearing 18; exhaust rocker arm bearing 19; intake rocker 20; exhaust rocker arm 21; roller 22; air intake valve 23; rotating shaft 24; drain tap 25; oil duct 26; rotating shaft 27; oil groove 28; bolt 29; valve adjustments bolt 30; lock nut 31; ball cup 32; air valve bridge 33.
Embodiment
In conjunction with Fig. 1 and Fig. 2, cylinder head has end face 1, be distributed with the air inlet side 2 of suction port, be distributed with the exhaust side 3 of relief opening, towards the front-end face 4 of timing train and the ear end face 5 relative with front-end face 4.Those of ordinary skills are to be understood that, end face 1 is relative cylinder head and cylinder block (not shown) bottom face in contact (unmarked) definition, and front-end face 4 and ear end face 5 are location definitions of relative timing train, also can adopt other definition mode certainly.On end face 1, be distributed with camshaft fitting seat 6, and be distributed with rocker arm support installation base 7 in its vicinity.Back oil road 8 begins to extend up to ear end face 5 from front-end face 4, thereby connects entire cylinder head between the front and rear end, as the part of cylinder lubrication oil circuit.
With reference to figure 3, owing to need dodge structure such as periphery such as water jacket 12 grades, the operative position alternative of back oil road 8 is very little, is positioned at the oblique below of rocker arm support installation base 7 substantially near the position of air inlet side 2.In the prior art, in order to provide lubricated to valve rocker (comprising intake rocker and exhaust rocker arm) assembly, the general mode of boring inclined oil hole of air 9 from rocker arm support installation base 7 that adopts is communicated to back oil road 8, so only needs once boring, and is easy to process.
With reference to figure 4, different with Fig. 3 is, the present invention gets out the first straight oilhole 10 straight down from 7 beginnings of rocker arm support installation base, 2 beginning levels are bored the second straight oilhole 11 from the air inlet side then, the first straight oilhole 10 intersects with the second straight oilhole 11 and is communicated with, and the second straight oilhole 11 is communicated with back oil road 8, thereby makes the fluid in the back oil road 8 arrive rocker arm support installation base 7 via the second straight oilhole 11, the first straight oilhole 10, further enter valve rocker.Certainly, in order not influence fuel feeding effect and engine performance, carry out shutoff processing the opening that needs it to be positioned at air inlet side 2 behind the second straight oilhole 11, method for blocking can adopt modes such as welding to carry out, but the preferred mode that press-fits blanking cover that adopts is carried out shutoff, because after cylinder head machines, generally need carry out the blanking cover shutoff to water hole, oilhole, utilize existing equipment and existing operation just can finish like this, and need on production line, not increase welding equipment and operation again.
With reference to 5, it has illustrate schematicallyd with inclined oil hole of air and has compared, and adopts the advantage of straight oilhole.In Fig. 5, represent the rotating locus of the cam on the camshaft 13 with circle, and under the situation that adopts inclined oil hole of air, all be represented by dotted lines, under the situation that adopts straight oilhole, all represent with solid line.When adopting inclined oil hole of air 9, the cam rotating locus of dashed circle representative arrives the tangent position of the inclined oil hole of air represented with dotted line 9 (certainly at the most, owing to the hole wall that has inclined oil hole of air 9 make dashed circle can not be real and inclined oil hole of air is tangent), this moment dashed circle to arrive the width of the opening of the inclined oil hole of air 9 on the rocker arm support installation base 7 be W1, namely the air inlet side 2 of the cylinder head minimum width that arrives these openings is under the prerequisite of the W1(thickness of not considering camshaft fitting seat 6); The height that dashed circle arrives back oil road 8 is H1.And adopt under the situation of the first straight oilhole 10 and the second straight oilhole 11, the center of circle C of dashed circle has arrived the C position, the center of circle of solid line circle, the cam rotation of the circular representative of solid line is estimated to arrive at the most with the tangent position of the first straight oilhole 10 of realizing expression and the second straight oilhole 11 (similar with above-mentioned situation, can not be really tangent), like this, the width W 2 that the air inlet side 2 of cylinder head arrives the opening of the first straight oilhole 10 can be significantly less than W1, and the circular height H 2 that arrives back oil road 8 of solid line can be significantly less than H1, that is to say, under the constant situation of other condition, compare with employing inclined oil hole of air 9, when adopting the first straight oilhole 10 and the second straight oilhole 11, the height of cylinder head and width can both further be reduced.Certainly, those of ordinary skills can understand, realize circular can not being if take place tangent with the tangent Another reason of the first straight oilhole 10, then camshaft will directly be pressed in the rotating shaft of valve rocker and can't drive valve rocker, but this does not hinder with adopting inclined oil hole of air 9 and compares cylinder head reducing on width, even the center of circle C of cam rotating locus moves straight down, reducing of cylinder width can not be brought although it is so, but still reducing of cylinder height can be brought.That is to say, after having adopted the first straight oilhole 10 and the second straight oilhole 11 to replace inclined oil hole of air 9, cylinder head can realize reducing on the height at least, perhaps can realize reducing on height, the width simultaneously, thereby this structure has realized the further miniaturization of motor, though the solution of the present invention need be carried out twice boring, this can bring the huge advantage that engine weight alleviates, the car load arrangement space is bigger, thus be possess cost-benefit.
With reference to figure 6, it has shown the concrete structure of the rocker arm support 14 that motor of the present invention adopts.Rocker arm support 14 comprises between intake rocker Support cushion 15 and exhaust rocker arm Support cushion 16, two Support cushions and being connected by bridging portion 17.Be installed with intake rocker bearing 18 and exhaust rocker arm bearing 19 on intake rocker Support cushion 15 and the exhaust rocker arm Support cushion 16 respectively.On the bottom surface of rocker arm support 14, have oil duct 26, oil duct 26 is communicated with the first straight oilhole 10, and the fluid that therefore comes from spill port 8 can enter intake rocker 20 and exhaust rocker arm 21, provides lubricated.Oil leab about valve rocker inside is all on the books in a plurality of patent documents and prior art document, and this paper no longer is described in detail.Each intake rocker Support cushion 15 and an exhaust rocker arm Support cushion 16 are a pair of, think that the intake rocker 20 of same firing chamber and exhaust rocker arm 21 provide support.In the present invention, have two pairs of intake rocker Support cushions 15 and exhaust rocker arm Support cushion 16 on each rocker arm support 14, therefore a rocker arm support can provide support for intake rocker 20 and the exhaust rocker arm 21 of two adjacent firing chambers, this has not only brought the convenience of installing, and be conducive to the control of installation precision, guarantee the timing synchronism of intake rocker 20 and the exhaust rocker arm 21 of adjacent firing chamber.
In conjunction with Fig. 2, Fig. 7, it has shown the valve rocker of the present invention concrete structure of (comprising intake rocker 20 and exhaust rocker arm 21).One end of valve rocker has roller 22, and the rotating shaft 27 of preferred roller 22 is made by the lead brass wire rod, possesses better wear resistance.Simultaneously, also have oil groove 28 in rotating shaft 27, the fluid that comes from back oil road 8 enters oil groove 28 and thinks between rotating shaft 27 and the roller 22 and provide lubricated.The other end of valve rocker is equipped with valve adjustments bolt 30, and the end of valve adjustments bolt 30 forms the bulb ball-and-socket with ball cup 32 and cooperates.Ball cup 32 presses down air valve bridge 33 along with the swing of valve rocker, thereby drive a pair of air intake valve 23 or a pair of drain tap 25, has realized that valve rocker and the driving of air intake valve or drain tap link.The setting height(from bottom) of air intake valve 23 and drain tap 25 is subjected to the adjusting of valve adjustments bolt 30 and finishes the adjusting back by lock nut 31 lockings.In the middle of two ends of valve rocker rotating shaft 24 is installed.During the motor assembling, camshaft 13 is installed in the camshaft fitting seat 6, rocker arm support 14 is installed on the rocker arm support installation base 7, thereby bolt 29 passes rotating shaft 24 intake rocker 20 and exhaust rocker arm 21 is fixedly installed to respectively on intake rocker bearing 18 and the exhaust rocker arm bearing 19, and intake rocker 20 and exhaust rocker arm 21 can be around its rotating shaft 24 swings.Thereby the cam on the camshaft 13 directly contacts with roller 22 and drives valve rocker.
With reference to figure 8, different for time of opening of time of opening of adapting to air intake valve 23 and drain tap 25, the axis a of the rotating shaft of intake rocker 20 and the axis b of the rotating shaft of exhaust rocker arm 21 are that parallel offset comes and do not overlap.
Though the present invention is described in conjunction with above embodiment, but the present invention is not defined to above-described embodiment, and only being subjected to the restriction of claim, those of ordinary skills can easily make amendment to it and change, but do not leave essence design of the present invention and scope.