JPH0210278Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) In the present invention, a camshaft that drives the intake valves to open and close and a camshaft that drives the exhaust valves to open and close are installed in parallel in the cylinder head, and a A recess is formed in the upper surface of the cylinder head in the longitudinal direction of the engine, and an ignition plug hole is drilled into the recess into which the ignition plug is inserted and fixed, while a timing belt that rotationally drives both of the camshafts is placed in front of the engine. This invention relates to a drainage structure on the upper surface of a cylinder head in an engine having such a structure.

(Prior art) In this type of engine, that is, in an engine in which a recess with a spark plug mounting hole is formed in the longitudinal direction of the engine between the camshafts on the top surface of the cylinder head, water tends to enter the recess during car washing, etc. Furthermore, if water enters the recess, it may damage the rubber plug cap of the ignition plug, impairing its durability, or the current from the ignition plug may leak, making it impossible to obtain a sufficient discharge voltage. Therefore, it is necessary to suppress the intrusion of water into the recess as much as possible, or to drain the water that has entered into the recess as quickly as possible. .

From this point of view, a known example of a device that prevents water from entering the recess between the camshafts on the top surface of the cylinder head is, for example,
There is one as shown in Japanese Patent No. 54-73410. In this known example, the left and right cylinder head covers that cover the upper parts of the left and right camshafts are integrated, and a part of the cylinder head covers covers the upper part of the recess between the camshafts, and the ignition plug is inserted into the cylinder head covers. A hole is formed, the ignition plug is installed from the ignition plug insertion hole to the ignition plug installation hole in the recess between the camshafts, and the ignition plug installation hole is sealed with an appropriate sealing material to prevent water from entering the recess. We are trying to prevent intrusions.

However, in this known example, the cylinder head cover is large and heavy, and the cost increases due to the increase in the number of parts.Furthermore, the sealing material must be attached and removed every time the ignition plug is attached and detached, making it difficult to ignite. There were some problems, such as the cumbersome work of attaching and detaching the stopper.

On the other hand, as a method for quickly discharging the water that has entered the recess between the camshafts, as in the latter case, conventionally the mounting angle of the engine relative to the vehicle body frame in the longitudinal direction is adjusted, thereby forcing the water inside the recess. A method was adopted in which the water flowed down to one side.

However, in this type of engine mounting angle that promotes the discharge of water from the recess, there are problems in terms of engine cooling performance, timing belt durability, etc., as will be described later. However, it was not possible to fully demonstrate its functions. That is, since the recess formed on the upper surface of the cylinder head is formed in a continuous groove shape over the entire longitudinal length of the cylinder head, the water is discharged toward the front of the engine. It is conceivable that the gas may be discharged to the rear of the engine.

First, when water is discharged to the front side of the engine, a timing belt for driving the camshaft is installed on the cylinder block wall at the front of the engine, and a timing belt is installed between the timing belt and the engine. The installed back plate has a through hole for auxiliary equipment such as an oil pump, so water discharged from the recess between the camshafts flows to the timing belt side through the auxiliary through hole in the back plate. However, there is a problem that the durability of the timing belt is reduced.

On the other hand, when water is to be discharged to the rear of the engine, a cooling water outlet is usually formed at the rear of the engine and in the center of the cylinder head, and this outlet also has a cooling water outlet located at the rear of the engine and in the center of the cylinder head. Since the thermostat is equipped with a jiggle pin that performs air bleeding, if the cooling water outlet is to be installed in the center of the cylinder head, the engine must be tilted significantly to the rear. The air bleeding effect of the jiggle pin of the thermostat will be impaired. On the other hand, if the cooling water outlet is offset from the center of the cylinder head to the left or right, the above-mentioned loss of the air bleeding effect by the jiggle pin of the thermostat can be prevented, but this time the cooling water circulation path can be reversed. It is not symmetrical with respect to the engine, and as a result, a problem arises in that the cooling characteristics of the engine deteriorate.

(Purpose of the invention) The purpose of the invention is to propose a simple drainage structure that can effectively drain water that has entered the recess of the cylinder head without impairing the cooling performance of the engine. It is something that

(Structure of the invention) In the cylinder head drainage structure of the invention, a camshaft that drives the intake valves to open and close and a camshaft that drives the exhaust valves to open and close are installed in parallel on the cylinder head, and the upper surface of the cylinder head between the two camshafts is arranged in parallel. A recess is formed in the longitudinal direction of the engine, and an ignition plug hole into which the ignition plug is inserted and fixed is bored. In an engine disposed within a belt cover equipped with a flat back plate disposed toward the front end of the cylinder head, the tie belt cover extends between the front end of the cylinder head and the tie belt cover, and corresponds to the end of the recess. A generally gutter-shaped drainage passageway in which a guide plate is disposed that slopes downward toward the side of the engine from a position where the water enters the recess, and the guide plate, the front end of the cylinder head, and the belt cover guide water that has entered the recess to the side of the engine. On the other hand, an engine cooling water outlet equipped with a thermostat with a jiggle pin is arranged at the rear center of the cylinder head, and the engine is mounted on the vehicle body at a mounting angle that slopes downward toward the front side. It is characterized by this.

(Embodiment) FIGS. 1 and 2 show an automobile engine Z having a cylinder head drainage structure according to an embodiment of the present invention. This engine Z has a first camshaft 9A for driving intake valves and a second camshaft 9B for driving exhaust valves.
In an O.H.C engine, these camshafts 9A and 9B are located in a first cam chamber 4A and a second cam chamber 4B formed on both sides of the cylinder head 2 in the width direction and facing in the longitudinal direction of the engine. are placed in each. The cam chambers 4A and 4B each have a rectangular bowl-shaped first cylinder head cover 3A.
and is covered by a second cylinder head cover 3B. Also, each of these camshafts 9A, 9B
, respectively, have one end passing through the side surface 2a of the cylinder head 2 on the front side of the engine and protruding toward the front side of the engine. Each of these camshafts 9A,
9B, the protruding end 9 of the first camshaft 9A
A first cam pulley 13A is attached to Aa, and a second cam pulley 13B is attached to the protruding end 9Ba of the second camshaft 9B. A timing belt 10 for driving a camshaft is wound around each of the cam pulleys 13A, 13B. The timing belt 10 is located closer to the cylinder head 2 than the timing belt 10, together with first and second cam pulleys 13A, 13B, a crank pulley 19, and a pulley for driving auxiliary equipment such as an oil pump or an idle pulley (not shown). A belt cover 12 having a back plate 11 that
is housed within. This belt cover 12 is
It is removably fastened to the front side surface 2a of the cylinder block 1. In addition, each camshaft 9A,
9B, the crankshaft 20, and an auxiliary shaft (not shown) protruding from the front side surface 1a of the cylinder block 1, all of which pass through the back plate 11 of the belt cover 12 in the inner and outer directions.

On the other hand, at the center of the cylinder head 2 in the width direction,
A recess 6 sandwiched between the first cam chamber 4A and the second cam chamber 4B is provided continuously in the longitudinal direction of the engine. Four spark plug mounting holes 8, 8, . These ignition plug mounting holes 8, 8, . . . have ignition plugs 7, 7, .
...is screwed on.

The outlet 17 of the cooling water passage 5 is formed on the side surface 2b of the cylinder head 2 on the engine rear side and on the central axis of the recess 6. A thermostat 18 with a jiggle pin 25 is interposed between this outlet 17 and an outlet connecting pipe 16 connected to the outlet 17.

Engine front side side 2a of cylinder head 2
As shown in FIG. 3, the concave portion 6 is inclined downwardly toward both ends of the side surface 2a with its apex located directly below the front opening end 6a, and has side portions 15a, 1 of the side surface 2a.
5a are both sides 1 in the width direction of the cylinder block 1
An eave-shaped guide plate 15 reaching the cylinder head 2 is integrally formed with the cylinder head 2. The front end surface 15b of this guide plate 15 is connected to the belt cover 1.
It is brought into substantially watertight contact with the back plate 11 of No. 2. A gutter-shaped drainage passage 14 allows the recess 6 and the side surface of the engine (the side surface of the cylinder block 1) to communicate with each other through the guide plate 15, the side surface 2a of the cylinder head 2, and the back plate 11. is formed. Furthermore, engine Z
is at the front of the engine (i.e. timing belt 10
It is mounted on the vehicle body frame at a mounting angle that tilts downward toward the installation side.

When the drainage passage 14 is formed as described above, water that has entered the recess 6 of the cylinder head 2 during car washing, etc., moves within the recess 6 toward the drainage passage 14 depending on the mounting angle of the engine, and the water is removed from the drainage passage 14. Both sides 1 in the width direction of the cylinder block 1 are passed through the passage 14.
b, 1b side, and further flows down to the lower part of the engine along the side surfaces 1b, 1b. In this way, all the water discharged from the inter-camshaft recess 6 is guided to both side surfaces 1b, 1b of the cylinder block 1 through the drainage passage 14, and a through hole for a shaft for an auxiliary machine such as an oil pump is formed. back plate 1
Since water does not flow into the lower part of the timing belt 1 (that is, the part corresponding to the front side surface 1a of the cylinder block 1), water enters the belt cover 12 through the through hole and deteriorates the quality of the timing belt 10. This will prevent problems from occurring.

Further, since the water that has entered the camshaft recess 6 is discharged from the front side of the engine, an outlet 17 for the cooling water passage 5 formed in the cylinder head 2 is provided at the rear central part of the cylinder head. This makes it possible to maintain good cooling characteristics of the engine.

In this embodiment, the guide plate 15 is formed integrally with the cylinder block 1, but in other embodiments of the present invention, the guide plate 15 may be formed, for example, on the back plate 11 side, or the guide plate 15 may be formed integrally with the cylinder block 1.
It is also possible to form the cylinder block 1 and the back plate 11 separately.

(Effect of the invention) In the cylinder head drainage structure of the invention, a camshaft that drives the intake valves to open and close and a camshaft that drives the exhaust valves to open and close are installed in parallel on the cylinder head, and the upper surface of the cylinder head between the two camshafts is arranged in parallel. A recess is formed in the longitudinal direction of the engine, and an ignition plug hole into which the ignition plug is inserted and fixed is bored. In an engine disposed within a belt cover equipped with a flat back plate disposed toward the front end of the cylinder head, the tie belt cover extends between the front end of the cylinder head and the tie belt cover, and corresponds to the end of the recess. A generally gutter-shaped drainage passageway in which a guide plate is disposed that slopes downward toward the side of the engine from a position where the water enters the recess, and the guide plate, the front end of the cylinder head, and the belt cover guide water that has entered the recess to the side of the engine. On the other hand, an engine cooling water outlet equipped with a thermostat with a jiggle pin is arranged at the rear center of the cylinder head, and the engine is mounted on the vehicle body at a mounting angle that slopes downward toward the front side. It is characterized by

Therefore, according to the cylinder head drainage structure of the present invention, (1) the engine is mounted on the vehicle body in a downwardly inclined state toward the front, and the engine is mounted at a position corresponding to the recess of the cylinder head at the front of the engine; Since a drainage passage is formed to drain the water that has entered the recess to the side of the engine, the water is reliably and easily drained to the side of the engine from this drainage passage, and the water does not enter the belt cover. (2) Among the members constituting the drainage passage, the back plate of the belt cover is shaped like a flat plate. ,
The abutting portions of the guide plates assembled to the back plate also have a linear structure, and as a result, these structures can be simplified and production efficiency can be improved, and the two are arranged in abutting state. (3) A cooling water outlet equipped with a thermostat with a jiggle pin is located at the rear center of the cylinder head, and the engine is mounted on the vehicle body. Since the corners are sloped downward toward the front of the engine, the jiggle pin can effectively bleed air, and the cooling water circulation path within the engine is symmetrical with respect to the axis of the engine, which facilitates cooling. Practical effects such as improved engine cooling performance with water, and the ability to drain water that has entered the cylinder head recess, engine cooling performance, and air bleed performance with a simpler structure. is obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional plan view of an automobile engine with a cylinder head drainage structure according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of FIG.
The figure is an enlarged perspective view of a portion of FIG. 2. 1... Cylinder block, 2... Cylinder head, 3... Cylinder head cover, 6... Recessed part,
7... Spark plug, 9A, 9B... Camshaft, 1
0...Timing belt, 11...Back plate, 12...Belt cover, 14...Drain passage,
15... Information board.

Claims (1)

[Scope of utility model registration request] A camshaft that drives the intake valves to open and close and a camshaft that drives the exhaust valves to open and close are arranged in parallel on the cylinder head, and a recess is formed in the upper surface of the cylinder head between the two camshafts in the longitudinal direction of the engine, and a recess is formed in the recess. An ignition plug hole is drilled into which the ignition plug is inserted and fixed, while a timing belt that rotationally drives both of the camshafts is installed.
In an engine disposed within a belt cover having a flat plate-shaped back plate disposed vertically at the front of the engine, a tie belt cover is provided between the front end of the cylinder head and the tie belt cover, and is arranged between the front end of the cylinder head and the tie belt cover. A guide plate is arranged that slopes downward toward the side of the engine from a position corresponding to the end of the recess, and the guide plate, the front end of the cylinder head, and the belt cover direct water that has entered the recess toward the side of the engine. An engine cooling water outlet equipped with a thermostat with a jiggle pin is arranged at the rear central part of the cylinder head, and the engine is tilted downward toward the front side. A cylinder head drainage structure characterized by being mounted on the vehicle body at the mounting angle.