JPH0868338A - DOHC engine accessory arrangement structure - Google Patents

Abstract

(57) [Abstract] [Purpose] By arranging the accessories corresponding to the shape of the cylinder head, the amount of overhang of the accessories from the engine body can be suppressed as much as possible, and therefore the compact DOHC engine including the accessories. Try to change. [Structure] Engine main body 1 having two camshafts 2 and 3
The camshafts 2 and 3 are connected by a gear or a chain 4 so that power can be transmitted, and a pulley 5 provided on one camshaft 2 is connected to a crankshaft 7 via a winding member (timing belt 6). In the rotationally driven DOHC engine, the shape of the cylinder head 13 of the engine body 1 is such that a portion of the end surface on the pulley 5 side corresponding to the pulley 5 is a bulging portion 13a, while the end surface on the opposite side of the pulley 5 is formed. As a straight portion 13b, and an auxiliary machine (for example, a power steering alternator 2) on the end surface side of the engine body 1 opposite to the pulley 5.
3) is arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DOHC engine auxiliary equipment arrangement structure.

[0002]

2. Description of the Related Art Engines mounted on automobiles include various auxiliary machines (for example, oil pumps for power steering,
Water pumps, alternators, air conditioner compressors, etc.) are attached, but in recent years, the types of these auxiliary machines have been increasing, and their layout has been devised to make the equipment compact in the engine room. Need to be elaborate.

Due to such demands, various arrangements of auxiliaries with respect to the engine body have been devised. For example, as disclosed in JP-A-6-108871,
There is an engine in which three auxiliary machines are intensively arranged on the front end face of a horizontal engine.

[0004]

By the way, in a DOHC engine, both cam shafts are connected by a gear or a chain so that power can be transmitted, and a pulley provided on one of the cam shafts is connected to a crank shaft via a winding member. Some are designed to be driven to rotate. DOHC with such a structure
In the case of an engine, it is necessary to bulge the side of the cylinder head where the pulley is arranged for the pulley arrangement. However, there is a problem in that it is difficult to achieve compact storage simply by arranging accessories in such an engine intensively as in the prior art.

The present invention has been made in view of the above points. By arranging the accessories corresponding to the shape of the cylinder head, the amount of overhang of the accessories from the engine body can be suppressed as much as possible. Therefore, the object is to make the DOHC engine including the auxiliary machinery compact.

[0006]

In the basic configuration of the present invention, as means for solving the above-mentioned problems, an engine body having two cam shafts is provided, and both cam shafts can transmit power by a gear or a chain. In a DOHC engine in which a pulley connected to one of the cam shafts is rotationally driven by a crank shaft via a winding member, a cylinder head shape of the engine body is a portion of the end face on the pulley side corresponding to the pulley. Is a bulge portion, the opposite end surface of the pulley is a straight portion, and an auxiliary machine is arranged on the end surface side of the engine body opposite to the pulley.

The basic configuration of the present invention has the following preferred embodiments.

That is, a plurality of auxiliaries including the auxiliaries are arranged along the end face of the engine main body on the side surface of the engine main body opposite to the pulleys. It is preferable because it is possible.

Further, the engine main body is mounted horizontally in the engine room with the side opposite to the pulley facing the front of the vehicle to lower the engine hood (in other words, lower the bonnet). It is preferable because it can be achieved.

Further, it is preferable that the plurality of auxiliary machines and the idler are arranged in a staggered manner in the vertical direction, and that they are rotationally driven by one winding member in order to obtain a compact arrangement of the plurality of auxiliary machines.

Further, an idler to be hooked on the winding member for driving the pulley is disposed inside the side cover corresponding to the side of the cylinder head, and outside the side cover, the idler is coaxial with the idler. It is preferable to dispose another auxiliary machine that is rotationally driven by the idler, because a large number of auxiliary machines can be efficiently driven in a compact layout.

Further, since the side cover is made of a high-rigidity material and the auxiliary machine is directly attached to the side cover, the auxiliary machine can be arranged without a dedicated bracket for mounting the auxiliary machine. preferable.

[0013]

In the basic structure of the present invention, the following actions can be obtained by the above means.

That is, an engine body having two cam shafts is provided, the both cam shafts are connected to each other by a gear or a chain so that power can be transmitted, and a pulley provided on one of the cam shafts is provided with a crank shaft via a winding member. In the DOHC engine configured to be rotationally driven by the auxiliary machine, the auxiliary machine is disposed on the bulging section side by disposing the auxiliary machine on the end surface side (in other words, the straight section side) of the cylinder head opposite to the pulley. The amount of overhang of the auxiliary machine from the engine body can be suppressed as much as possible compared to the case where the machine is provided.

In the preferred embodiment of the basic configuration of the present invention, the following actions are obtained.

That is, when a plurality of auxiliary machines including the auxiliary machine are arranged along the end surface of the engine main body on the side surface of the engine main body opposite to the pulley, a large number of auxiliary machines are integrated and compactly arranged. Therefore, the engine including the auxiliary machinery can be made compact.

Further, when the engine body is mounted horizontally in the engine room with the side opposite to the pulley facing the front of the vehicle, the engine hood is reduced by reducing the amount of overhang from the engine body of the auxiliary machine. Can be lowered (in other words, the bonnet can be lowered).

Further, when the plurality of accessories and the idler are arranged in a staggered manner in the vertical direction and are driven to rotate by one winding member, the plurality of accessories and the idler are compact in the vertical direction. Therefore, the engine including the auxiliary machinery can be made compact.

Further, an idler to be hooked on the winding member for driving the pulley is arranged inside the side cover corresponding to the side of the cylinder head, and outside the side cover, the idler is coaxial with the idler. When another auxiliary machine that is driven to rotate by the idler is installed on the upper side, it is possible to obtain an auxiliary machine arrangement that uses a dead space outside the idler. It can be driven with a simple layout.

When the side cover is made of a high-rigidity material and the accessory is directly attached to the side cover, the accessory can be arranged without a dedicated bracket for mounting the accessory.

[0021]

According to the basic constitution of the present invention, the engine main body having two cam shafts is provided, the both cam shafts are connected by a gear or a chain so that power can be transmitted, and a pulley provided on one cam shaft. In a DOHC engine configured to be rotatably driven by a crank shaft via a winding member, an auxiliary machine is arranged on an end face side (in other words, a straight portion side) of the cylinder head opposite to the pulley. As a result, the amount of overhang of the auxiliary machine from the engine body can be suppressed as much as possible compared to the case where the auxiliary machine is arranged on the bulging side, and the engine including the auxiliary machine can be made compact. It has an excellent effect of making a great contribution.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

The DOHC engine of this embodiment is provided with an engine body 1 having two cam shafts 2 and 3, and both cam shafts 2 and 3 are connected by a chain 4 so that power can be transmitted. In this case, the pulley 5 provided on the cam shaft 2 on the rear side is rotationally driven by the crank shaft 7 via the timing belt 6 which is a winding member.
It is mounted horizontally in the engine compartment 8 with the side opposite to the pulley facing the front of the vehicle and slanted on the side opposite to the pulley 5. In addition,
Both camshafts 2 and 3 may be connected via a gear so that power can be transmitted. Reference numerals 9 and 10 are sprocket wheels provided on the cam shafts 2 and 3, 11 is a cam shaft driving pulley pivotally supported on the outer end of the crank shaft 7, and 12 is an engine hood.

The shape of the cylinder head 13 in the engine body 1 is such that the pulley 5 at the end face on the pulley side is formed.
The portion corresponding to is a bulging portion 13a, while the opposite side of the pulley 5 is a straight portion 13b.
The side cover 14 corresponding to the side surface of the cylinder head 13 is made of an integrally molded product of a high-rigidity material (for example, metal such as cast iron), and the upper cover 15 covering the upper part of the cylinder head 13 is made of synthetic resin. It is composed of an integrally molded product, and the engine cover is composed by connecting the both. Here, the side cover 14 is attached to the side surface of the engine body 1 by the bolt 2
It is attached by 1, 21 ... The side cover 14 may be made of metal such as cast iron or the like, or high rigidity material such as ceramic or powder metal.

An idler 16 for guiding the timing belt 6 to a position opposite to the pulley 5 with respect to the cylinder axis O ₁ is provided on the inner surface of the side cover 14 as a rotary shaft of a vacuum pump 19 described later. 19
It is arranged so as to be pivotally supported by a. Reference numerals 17, 18
Is an idler for guiding the timing belt 6. That is, the timing belt 6 includes the cam shaft driving pulley 11,
The idler 17, the idler 16, the pulley 5 and the idler 18 are wound around, and the driving force of the crankshaft 7 is transmitted to the pulley 5 via the timing belt 6.

On the outer surface side of the side cover 14, a vacuum pump 19 which is an auxiliary machine which is driven to rotate coaxially with the idler 16 by the idler 16 and an opposite side of the vacuum pump 19 with respect to the cylinder axis O _1. And an engine mount 20 for supporting the engine body 1 with respect to the vehicle body.

The vacuum pump 19 is directly fixed to the outer surface of the side cover 14 by bolts 22, 22 ... And the idler 16 is pivotally supported on the rotary shaft 19a thereof as described above. . On the other hand, the engine mount 20 is located above the crankshaft 7 on the vertical centerline O ₂ and is integrally formed with the side cover 14.

With the above-mentioned structure, the vacuum space 19 which is one of the auxiliary machines can be disposed by effectively utilizing the dead space existing on the outer side of the idler 16, and the engine mount 20 can be mounted on the engine mount 20. Even on the pulley 5 side on the side surface of the main body 1, it can be arranged at a high position without interfering with the pulley 5. Moreover, since the vacuum pump 19 is an auxiliary machine having a relatively small rotational inertia, there is no fear that an excessive load is applied to the side cover 14, and the rigidity of the side cover 14 can be easily secured. In addition,
By attaching the vacuum pump 19 directly to the side cover 14, a dedicated mounting bracket or the like is not required, which can contribute to simplification of the structure and cost reduction.

On the end face side of the cylinder head 13 of the engine body 1 opposite to the pulley 5 (in other words, the straight portion 13b side), an oil pump 23 for power steering, which is one of the auxiliary machines, is provided. Below the power steering oil pump 23, a plurality of other auxiliary machines such as an alternator 24, an air conditioner compressor 25, and idlers 31 and 32 are arranged in a staggered arrangement in the vertical direction. Then, these auxiliary machines (that is, the power steering oil pump 23, the alternator 24, and the air conditioner compressor 25).
Is rotatably driven by one winding member (that is, the accessory drive belt 30) by the crankshaft pulley 26 pivotally supported by the crankshaft 7. Here, the idler 31 is fixed and the idler 32 is movable.

With the above configuration, the power steering oil pump 23 overhangs from the engine body 1 as compared with the case where the power steering oil pump 23 is disposed on the bulging portion 13a side of the cylinder head 13. The amount can be suppressed as much as possible, which greatly contributes to downsizing of the engine including the power steering oil pump 23. Moreover, the engine body 1
However, since it is mounted horizontally in the engine room 8 with the end surface opposite to the pulley 5 facing the front of the vehicle, the amount of overhang of the power steering oil pump 23 from the engine body 1 is Due to the reduction, the engine hood 12 can be lowered (in other words, the hood can be lowered).

A plurality of auxiliary machines (alternator 24 and air conditioner compressor 25) including the power steering oil pump 23 are provided on the side surface of the engine body 1 opposite to the pulley 5 along the end surface of the engine body 1. By arranging in such a manner, a large number of accessories can be integrated and compactly arranged, and the engine including the accessories can be made compact. Moreover, these auxiliary machines (that is, the power steering oil pump 23,
Alternator 24 and air conditioner compressor 25)
And the idlers 31 and 32 are arranged in a zigzag pattern in the vertical direction, and are driven to rotate by one accessory drive belt 30, so that a plurality of accessories (that is, the oil pump 23 for power steering, the alternator 24).
And air conditioner compressor 25) and idler 31,
32 and 32 can be compactly arranged in the vertical direction, and the engine including the auxiliary machine can be made compact.

Further, a supercharger 33 is disposed on the anti-slant side (in other words, the rear surface side) of the engine body 1, and the pulley 34 of the supercharger 33 has a pulley 34.
It is to be rotatably driven by another crank shaft pulley 37 via a drive belt 38 together with a pulley 36 of a water pump 35 provided inside the cylinder shaft O ₁ . Reference numeral 39 is a fixed idler. Here, the drive belt 38 is the side cover 1
4 is arranged so as to pass through the outside. The reason why such a layout is possible is that the engine mount 20 is provided at a high position in the side cover 14 as described above.

As described above, by disposing the supercharger 33, which is a heavy object, on the anti-slant side of the engine body 1,
This makes it easier to balance the weight of the entire engine.

The invention of the present application is not limited to the configuration of the above-mentioned embodiment, and it goes without saying that the design can be appropriately changed without departing from the gist of the invention.

[Brief description of drawings]

FIG. 1 is a side view showing a structure of an auxiliary machine of a DOHC engine according to an embodiment of the present invention.

FIG. 2 is a plan view showing a positional relationship between an engine main body and a side cover in the DOHC engine auxiliary equipment arrangement structure according to the embodiment of the present invention.

FIG. 3 is a front view showing the positional relationship between the engine body and the side cover in the DOHC engine auxiliary equipment arrangement structure according to the embodiment of the present invention.

FIG. 4 is a side view showing a positional relationship between an engine main body and a side cover in the DOHC engine auxiliary equipment arrangement structure according to the embodiment of the present invention.

[Explanation of symbols]

1 is the engine body, 2 and 3 are camshafts, 4 is a chain, and 5
Is a pulley, 6 is a winding member (timing belt), 7 is a crankshaft, 8 is an engine room, 12 is an engine hood, 13 is a cylinder head, 13a is a bulging portion, 13b is a straight portion, 14 is a side cover, 16 Is idler, 1
9 is an auxiliary machine (vacuum pump), 20 is an engine mount, 23 is an auxiliary machine (oil pump for power steering), 24 is an auxiliary machine (alternator), 25 is an auxiliary machine (air conditioner compressor, 30 is an auxiliary machine drive belt, 31, 3
2 is an idler.

Front page continued (72) Inventor Tsunehiro Mori 3-1, Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Inventor Naohide Iso Iso 3-1, Shinchu, Fuchu-cho, Hiroshima Prefecture Mazda Co., Ltd.

Claims (6)

[Claims] 1. An engine main body having two cam shafts, the cam shafts being connected to each other by a gear or a chain so that power can be transmitted, and a pulley provided on one cam shaft is provided with a crank shaft via a winding member. Driven by DOH
In the C engine, the cylinder head shape of the engine body is such that a portion of the end surface on the pulley side corresponding to the pulley is a bulge portion, while an end surface on the opposite side of the pulley is a straight portion. An auxiliary machine arrangement structure for a DOHC engine, characterized in that an auxiliary machine is arranged on the end face side opposite to the pulley. 2. A plurality of auxiliary machines including the auxiliary machine are arranged along a side surface of the engine main body opposite to the pulley along an end surface of the engine main body. The structure for arranging accessories of the DOHC engine described above. 3. The engine body according to claim 1 or 2, wherein the engine body is installed horizontally in an engine room with the side opposite to the pulley facing the front of the vehicle. 2. A structure for arranging accessories of a DOHC engine as described in 1 above. 4. The plurality of auxiliaries and the idler are arranged in a staggered manner in the vertical direction, and are driven to rotate by one winding member. 2. A structure for arranging accessories of a DOHC engine as described in 1 above. 5. An idler hooked on the winding member for driving the pulley is disposed inside a side cover corresponding to a side of the cylinder head, and the idler is provided outside the side cover. 5. Another auxiliary machine, which is rotationally driven by the idler, is disposed coaxially with the D, according to any one of claims 1 to 4.
Auxiliary equipment structure of OHC engine. 6. The auxiliary machine arrangement structure for a DOHC engine according to claim 5, wherein the side cover is made of a highly rigid material, and the auxiliary machine is directly attached to the side cover. .