JP3426373B2 - Slant engine cylinder head structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head structure of a slant engine which is mounted mainly under a vehicle seat with a cylinder inclined. 2. Description of the Related Art Conventionally, in a slant engine in which a cylinder head is mounted to be inclined at a small angle from the horizontal, when mounted on a vehicle, an exhaust manifold is located below the cylinder due to the shape of the mounting space. The fuel pump is located at the front end of the cylinder head, and the cooling water introduced into the water jacket from the front end is led out from the rear end of the cylinder block toward the radiator. In a so-called front engine rear drive type vehicle in which the engine is mounted on the front of the vehicle and the rear wheels are driven, a thermostat and a water pump are attached to the front of the cylinder block, and cooling water is supplied from the front of the cylinder block into the water jacket. It is known that it is introduced into a radiator from a cylinder head (for example, Japanese Patent Application Laid-Open No. 4-284124). [0003] By the way, the slant engine has a structure in which the air mixed in the cooling water hardly escapes from the circulation path of the cooling water due to its mounting posture. Therefore, it may be necessary to provide a dedicated valve in the circulation path of the cooling water in order to extract the air. Further, when cooling water is introduced from a cylinder block, as in the case of an engine of a front engine rear drive type vehicle, it is difficult to attach a thermostat or the like directly to the cylinder block, and it has been difficult to apply the invention to a slant engine. [0004] In addition to the above, when the fuel pump is heated by an exhaust system pipe disposed below and behind the mounting space, vapor is generated in the fuel, so that the fuel pump is least affected by the temperature. Need to be attached to For this reason, the fuel pump is usually mounted on the upper end of the front part of the cylinder head.However, mechanical fuel pumps tend to have a structure that makes it difficult to lubricate the lubricating oil. The structure is difficult to lower the height. [0005] An object of the present invention is to solve such a problem. The present invention has the following means to attain the above object. That is, the cylinder head structure of the slant engine according to the present invention has a circulation path in which a liquid for cooling the cylinder block and the cylinder head circulates, and the cylinder head is inclined upward with respect to a horizontal plane on which the cylinder head is a reference. At the front position of the side of the cylinder head of the slant engine mounted in the state, equipped with a mechanical fuel pump having a pump chamber for delivering fuel to the intake system so as to be located substantially perpendicular to the horizontal plane, An introduction opening for introducing the liquid from the outside of the cylinder head is provided on the front surface of the cylinder head near the mounting position of the mechanical fuel pump, and an outlet opening for leading the liquid to the outside from the inside of the cylinder head is provided by the mechanical type. It is provided on the side of the cylinder head near the mounting position of the fuel pump. With such a construction, the mechanical fuel pump is provided at a position in front of the side surface of the cylinder head so as to be substantially perpendicular to the horizontal plane, so that the entirety of the slant engine is provided. Lower the height. In addition, the introduction opening is located on the front of the cylinder head near the mounting position of the mechanical fuel pump,
In addition, by providing the outlet opening on the side of the cylinder head near the mounting position of the mechanical fuel pump, it is easy to take out the air bubbles mixed into the liquid from the outlet opening. Thereby, since the bubbles are eliminated, the cooling efficiency for the cylinder head and the cylinder block by the liquid can be increased. An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a DOHC slant engine (hereinafter, simply referred to as an engine) 100 in which two overhead camshafts (hereinafter, referred to as camshafts) 2 are driven by a scissors gear 1, which is mounted on a vehicle. In this case, the cylinder head 3 is mounted in a state where the cylinder head 3 is inclined upward with respect to a horizontal plane P serving as a reference of the vehicle. That is, the engine 100 is provided with a circulation path for circulating cooling water as a liquid for cooling the cylinder block 9 and the cylinder head 3, that is, a water jacket (not shown), and the cylinder head 3 is used as a reference. It is mounted in a state inclined upward with respect to the horizontal plane P. A mechanical fuel pump 4 is attached to a portion near the front end of the cylinder head 3, which is the highest position when the engine 100 is mounted on a vehicle, and is not shown on the side. A water outlet 7 is provided on the flange of the intake manifold and attached to the outlet 6 for cooling water. Further, a cooling water introduction opening 8 is provided in a front wall 33 on the front surface of the cylinder head 3 near the mechanical fuel pump 4. That is, the cylinder head 3 is provided with a mechanical fuel pump 4 provided with a pump chamber 41 for sending fuel to an intake system at a position in front of a side surface thereof so as to be positioned substantially perpendicular to the horizontal plane. A vertical opening 31 for introducing cooling water from the outside to the inside is provided on the front surface near the mounting position of the mechanical fuel pump 4 and the cooling water is drawn from the inside to the outside. Is provided on a side surface near the mounting position of the mechanical fuel pump 4. The vertical side wall 31 is different from the side wall 32 provided with the intake opening 39 for the intake manifold, and the surface of the side wall 32 for the intake manifold is substantially parallel to the central axis of the cylinder. , Are formed so as to be substantially perpendicular to a horizontal plane P serving as a reference. The vertical side wall 31 is formed so as to be located on the side of the eccentric cam 38 disposed near the front wall 33 in the longitudinal direction of the cylinder head 3 substantially at the center.
An opening 34 is provided corresponding to the opening 45 formed in the mounting surface 46 of the fuel pump 4. A guide hole 35 through which the push rod 5 is inserted is formed on the inner wall on the back side of the opening 34.
And a space Ss in which the scissors gear 1 is provided and the opening 3
4 and a supply passage 3 composed of a through hole through which lubricating oil passes.
6 are provided. That is, the center of the opening 34 is
The push rod 5 is located on the same line as the center in the thickness direction of the eccentric cam 38 provided adjacent to the bearing 37, and the push rod 5
And reaches the lever 44 of the fuel pump 4. Furthermore, such an eccentric cam 3
8, the space Ss where the scissors gear 1 is located at a position separated by the bearing 37 of the camshaft 2 and the opening 34 efficiently introduce the lubricating oil droplets scattered from the scissors gear 1 into the supply passage 36. And a collection space Sc for communication with the supply passage 36. As shown in FIG. 4, the collection space Sc is formed to be curved in accordance with the outer shape of the scissors gear 1, so that the scattered lubricating oil can easily flow into the supply passage. When the cylinder head 3 is viewed from the front, the introduction opening 8 is located below one of the camshafts, has a substantially circular opening shape, and is provided inside the cylinder head 3 and the cylinder block 9. It is designed to communicate with the water jacket. A thermostat as a valve body for selectively introducing cooling water derived from a radiator (not shown) into the water jacket is attached to the introduction opening 8. Further, the outlet opening 6 is provided in the side wall 32 near the front end of the cylinder head 3 close to the intake opening 39, and communicates with the water jacket similarly to the introduction opening 8. The water outlet 7 attached to the outlet opening 6 is connected to a radiator mounted in front of the engine 100 by a tube (not shown) as shown in FIGS. 1 and 5 to 6 and connects a pipe to the radiator. Opening 72 of main tube 71
However, like the introduction opening 8, it is disposed facing the front of the engine 100. That is, the main tube 71 is attached to the mounting surface 7.
3, it is formed so as to be inclined downward and to be directed substantially forward in the horizontal direction when attached to the cylinder head 3. The mechanical fuel pump 4 has a pump shaft 43 for reciprocating a diaphragm 42 which is a membrane member for changing the capacity of a pump chamber 41 for sending fuel to an intake system, and the pump shaft 43 as a driving system for a valve element. A lever body 44 that reciprocates in accordance with the rotation of the camshaft 2 is internally provided such that the respective longitudinal directions intersect substantially at right angles, and one end 44 a of the lever body 44 is engaged with the lower end of the pump shaft 43. And a mounting surface 46 having an opening 45 and formed substantially in parallel with the pump shaft 43 near the other end of the lever body 44.
(Shown in FIG. 2). That is, in the fuel pump 4, the pump housing 47 is substantially divided into two by the diaphragm 42, and the pump chamber 41 is provided above the diaphragm 42.
An atmosphere chamber 48 and a mechanism chamber 49 are formed below the lower side. The structure of the pump chamber 41 may be the same as the conventional one, and the valve element 41b attached to the communication port 41a moves in the opposite directions by the operation of the diaphragm 42, respectively.
The fuel is supplied to an intake system (not shown). The air chamber 48 has a small hole 48a
Are provided so as to communicate with the outside. Atmosphere chamber 48
The mechanism chamber 49 is separated from the mechanism chamber 49 by an oil seal 49 a so that the lubricating oil introduced into the mechanism chamber 49 does not enter the atmosphere chamber 48. This oil seal 49
A pump shaft 43, which passes through the center of “a” and whose upper end is connected to the lower surface of the diaphragm 42, extends substantially vertically to near the bottom surface of the mechanism chamber 49. The diaphragm 42 connected to the pump shaft 43 is constantly urged upward by a coil spring 48b disposed around the pump shaft 43 in the atmosphere chamber 48. Similarly, the pump shaft 43
Lever body 4 engaged with flange 43a provided at the lower end thereof
4 is always urged downward. This lever body 44
Has a substantially L-shaped side view, the end 44a of the horizontal piece 44A engages with the flange 43a of the pump shaft 43, and the upper end 44b of the vertical piece 44B connected to the horizontal piece 44A has a push rod 5 A rod receiving portion 44c is formed in contact with the vertical piece 44B.
Are urged toward the mounting surface 46 side. In such a configuration, when the cylinder head 3 is assembled, the fuel pump 4 is assembled to the cylinder head 3. First, the push rod 5 is inserted into the guide hole 35 of the cylinder head 3. One end of the push rod 5 is always in sliding contact with the outer peripheral portion of the eccentric cam 38, and the other end projects outward from the opening 34 when sliding on the outer peripheral portion farthest from the center. It has been set. Thereafter, the fuel pump 4 is mounted on the vertical side wall 31 with the openings 34 and 45 aligned. Since the fuel pump 4 is mounted on the vertical side wall 31 formed on the cylinder head 3, the camshaft 2 is arranged two cylinders higher than that of the single overhead camshaft (SOHC) engine having the same displacement, and the cylinder head 3 However, the height of the entire engine including the fuel pump 4 is not much different from that of the SOHC engine, and it can be considered that the height can be reduced as much as the cylinder head 3 becomes larger. it can. Further, the mechanism chamber 49 in which the lever body 44 is accommodated is disposed substantially horizontally, so that the mechanism chamber 49 exists substantially on the extension of the supply passage of the cylinder head 3, and the rotation of the scissors gear 1 causes The generated splash of the lubricating oil easily reaches the engaging portion between the pump shaft 43 and the lever body 44 and the rotating shaft portion of the lever body 44, so that wear caused by insufficient lubricating oil can be suppressed. In the fuel pump 4 integrally mounted on the engine 100, the eccentric cam 38 reciprocates the push rod 5 in the guide hole 35 by the rotation of the cam shaft 2, and the push rod 5 Body 44
When is pressed, the pump shaft 43 operates up and down, and the diaphragm 42 moves up and down. As a result, the capacity of the pump chamber 41 changes, and fuel is introduced into the pump chamber 41. When the capacity is minimized, the fuel is delivered to the intake system, and in some cases, is returned to the fuel tank. Next, a thermostat is fitted and attached to the introduction opening 8 in a watertight state. That is, the thermostat is directly attached to the cylinder head 3 without a member for auxiliary attachment only, and the number of members required for attachment is reduced. In addition, since the introduction opening 8 is provided on the front surface of the engine 100, the work of attaching the thermostat, including the work of tightening bolts for fixing, becomes extremely easy. In addition, since the opening direction is directed forward, piping can be performed almost straight to the radiator without detouring, and the piping itself can be shortened. The attachment of the water outlet 7 is performed after the attachment of the intake manifold. After fixing the intake manifold to the side wall 32 of the cylinder head 3, the water outlet 7 is attached with two bolts by bringing the mounting surface 73 into close contact with the flange of the intake manifold.
An opening having the same shape as the outlet opening 6 is provided in the flange, and the outlet opening 6, the opening of the flange, and the opening of the mounting surface of the water outlet 7 overlap each other. Since the main tube 71 of the water outlet 7 attached in this manner is directed to the front of the engine 100, piping with the radiator is facilitated. In addition, since the outlet opening 6 is formed at a high position in the front end portion of the engine 100, air bubbles mixed in the cooling water are guided to the outlet opening 6 together with the circulation of the cooling water and discharged from the water jacket. Becomes Therefore, a separate member such as a discharge valve for discharging air bubbles to the cooling water circulation path including the water jacket is not required. The present invention is not limited to the embodiment described above. In the above embodiment, the structure of the cylinder head in the DOHC slant engine has been described, but the present invention is also applicable to the SOHC slant engine. That is, also in the SOHC slant engine, a side wall substantially perpendicular to a horizontal plane which is a reference at the time of mounting is formed on the cylinder head, the mechanical fuel pump 4 is attached to the substantially vertical side wall, and a lead-out opening is provided on a side surface in the vicinity thereof.
Also, an introduction opening may be formed on the front surface. In addition, the configuration of each section is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention. According to the present invention, as described in detail above, a cooling liquid introduction opening is provided on the front surface of the cylinder head, and a mechanical fuel pump and a discharge opening are provided on the side surface near the opening. With this arrangement, air bubbles mixed into the liquid can be easily taken out from the outlet. Therefore, since the bubbles are eliminated, the cooling efficiency of the liquid to the cylinder head and the cylinder block can be increased.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing one embodiment of the present invention. FIG. 2 is a front view of the cylinder head with the mechanical fuel pump and the water outlet of the embodiment attached. FIG. 3 is a side view of the cylinder head of the embodiment. FIG. 4 is a plan view showing a main part of the cylinder head of the embodiment. FIG. 5 is a side view of the water outlet of the embodiment. FIG. 6 is a plan view of the water outlet of the embodiment. FIG. 7 is a sectional view of the mechanical fuel pump of the embodiment. [Description of Symbols] 2 ... Overhead camshaft 3 ... Cylinder head 4 ... Mechanical fuel pump 6 ... Outlet opening 7 ... Water outlet 8 ... Introduction opening 9 ... Cylinder block 33 ... Front wall 32 ... Side wall P ... Reference horizontal plane

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02B 67/00 F01P 3/02 F01P 3/18 F02M 37/20

Claims (1)

(57) [Claim 1] A circulation path for circulating a liquid for cooling the cylinder block and the cylinder head is provided therein. The cylinder head is inclined upward with respect to a reference horizontal plane. At the front position of the side of the cylinder head of the slant engine mounted in the state, equipped with a mechanical fuel pump having a pump chamber for delivering fuel to the intake system so as to be located substantially perpendicular to the horizontal plane, An introduction opening for introducing the liquid from the outside of the cylinder head is provided on the front surface of the cylinder head near the mounting position of the mechanical fuel pump, and an outlet opening for leading the liquid to the outside from the inside of the cylinder head is provided by the mechanical type. A cylinder head structure for a slant engine, which is provided on a side surface of a cylinder head near a mounting position of a fuel pump.