CN108138691B

CN108138691B - Cooling structure of cylinder head

Info

Publication number: CN108138691B
Application number: CN201680055975.1A
Authority: CN
Inventors: 早崎纲记
Original assignee: Isuzu Motors Ltd
Current assignee: Isuzu Motors Ltd
Priority date: 2015-09-30
Filing date: 2016-09-06
Publication date: 2020-07-07
Anticipated expiration: 2036-09-06
Also published as: JP2017066997A; CN108138691A; JP6665472B2; WO2017056869A1

Abstract

A cylinder head cooling structure, in the cooling structure, a plurality of cylinders (11A-11C) are arranged in series, air inlet ports (13A, 13B) and exhaust ports (12A, 12B) are arranged on the cylinders (11A-11C), and a cylinder head bolt boss part (15) is arranged on the exhaust side between the cylinders (11A-11C); the cylinder head cooling structure includes: a cooling water introduction unit (25) that is provided below the exhaust ports (12A, 12B) and that introduces cooling water into the cylinder head (1); boss-side cooling water flow paths (27A, 27B) which branch from the cooling water introduction section (25) and extend in the vicinity of the cylinder head bolt boss section (15); an inter-cylinder cooling water channel (23) which extends between the plurality of cylinders (11A-11C) and the upstream end of which merges with the boss-side cooling water channels (27A, 27B); an inter-exhaust-port cooling water flow path (26A) which branches from the cooling water introduction section (25) and extends between the exhaust ports (12A, 12B); and cutoff walls (70-74) that cut off the flow of cooling water from the cooling water introduction section (25) through the boss-side cooling water flow paths (27A, 27B).

Description

Cooling structure of cylinder head

Technical Field

The present invention relates to a cooling structure for a cylinder head.

Background

In general, since the spark contact surface of the cylinder head is likely to reach a high temperature, a cooling structure is employed in which a cooling water flow path is provided around the exhaust port or the injector boss portion, thereby reducing the temperature of the cylinder head.

For example, patent document 1 discloses a cylinder head cooling structure in which a cylinder head including a pair of exhaust ports in each cylinder is provided with an inter-exhaust port flow path extending between the exhaust ports so that cooling water is supplied to the exhaust ports or the vicinity of an injector boss portion, which most easily reaches a high temperature.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-113706

Disclosure of Invention

Problems to be solved by the invention

In general, the cooling water supplied to the cylinder head is introduced from a water jacket in the cylinder block to a cooling water introduction portion formed below an exhaust port of the cylinder head. The cooling water introduction portion is connected to a flow path between exhaust ports, a cylinder head bolt boss bypass flow path that flows in the vicinity of the cylinder head bolt boss portion, or the like. Further, an exhaust port upper flow path extending in the crankshaft axial direction (longitudinal direction) of the engine is formed above the inter-exhaust port flow path, and an inter-cylinder flow path extending in the width direction of the engine between the cylinders is also formed between the cylinders.

In such a flow path structure, there is a possibility that: the cooling water introduced from the cylinder block into the cooling water introduction portion flows from the head bolt boss bypass passage to the inter-cylinder passage or the upper exhaust port passage without being supplied to the inter-exhaust port passage having a high temperature, and the cooling efficiency of the cylinder head is lowered.

The cooling structure of the present invention is intended to improve the cooling efficiency of a cylinder head by effectively securing the flow rate of cooling water from a cooling water introduction portion of the cylinder head to an inter-exhaust port passage.

Means for solving the problems

A cooling structure of the present invention is a cooling structure of a cylinder head in which a plurality of cylinders are arranged in series in a longitudinal direction of an engine, a pair of intake ports and a pair of exhaust ports are arranged in the cylinders in the longitudinal direction of the engine, respectively, and a cylinder head bolt boss portion is provided on an exhaust side between the cylinders; the cooling structure of the cylinder head includes: a cooling water introduction unit that is provided below the exhaust port and introduces cooling water supplied from the cylinder block side into the cylinder head; a boss-side cooling water flow path which branches from the cooling water introduction part and extends in the vicinity of the engine inner side of the cylinder head bolt boss part; an inter-cylinder cooling water flow path extending in the width direction of the engine between the plurality of cylinders, and an upstream end of which merges with the boss bypass cooling water flow path; a 1 st inter-exhaust-port cooling water flow path which branches from the cooling water introduction part and extends between the pair of exhaust ports; and a cutoff wall provided in the boss bypass cooling water flow passage, and cutting off a flow of the cooling water from the cooling water introduction portion to the inter-cylinder cooling water flow passage through the boss bypass cooling water flow passage.

A cooling structure of the present invention is a cooling structure of a cylinder head in which a plurality of cylinders are arranged in series in a longitudinal direction of an engine, a pair of intake ports and a pair of exhaust ports are arranged in the cylinders in the longitudinal direction of the engine, respectively, and a cylinder head bolt boss portion is provided on an exhaust side between the cylinders; the cooling structure of the cylinder head includes: a cooling water introduction unit that is provided below the exhaust port and introduces cooling water supplied from the cylinder block side into the cylinder head; a boss-side cooling water flow path which branches from the cooling water introduction part and extends in the vicinity of the engine inner side of the cylinder head bolt boss part; an inter-cylinder cooling water flow path extending in the width direction of the engine between the plurality of cylinders, and an upstream end of which merges with the boss bypass cooling water flow path; a 1 st inter-exhaust-port cooling water flow path which branches from the cooling water introduction part and extends between the pair of exhaust ports; and a 1 st cutoff wall that is provided in the inter-cylinder cooling water flow path and cuts off the flow of cooling water from the cooling water introduction portion to the inter-cylinder cooling water flow path via the boss bypass cooling water flow path.

May further include: an exhaust port upper cooling water flow path extending in a longitudinal direction of the engine above the exhaust port and merging with a downstream end of the boss side cooling water flow path; and a 2 nd cutoff wall that is provided in the inter-cylinder cooling water flow path and cuts off the flow of cooling water from the cooling water introduction portion to the exhaust port cooling water flow path via the boss bypass cooling water flow path.

May further include: an inter-intake/exhaust port flow path extending in the longitudinal direction of the engine between the exhaust port and the intake port and merging with a downstream end of the 1 st inter-exhaust port cooling water flow path; a 2 nd inter-exhaust-port cooling water flow path which branches upward from the 1 st inter-exhaust-port cooling water flow path and whose downstream end merges with the above-exhaust-port upper cooling water flow path; and a 3 rd cutoff wall that is provided in the 2 nd inter-outlet cooling water flow path and cuts off the flow of cooling water from the cooling water introduction portion to the 2 nd inter-outlet cooling water flow path through the 1 st inter-outlet cooling water flow path.

The cylinder head may further include an outer boss bypass cooling water passage that branches from the cooling water introduction portion and extends in a longitudinal direction of the engine outside the cylinder head bolt boss portion.

The cooling water supply device may further include a protrusion portion provided to protrude into the cooling water introduction portion by a predetermined protruding amount, and throttling a flow path of the cooling water from the cooling water introduction portion to the boss bypass cooling water flow path.

Effects of the invention

According to the cooling structure of the present invention, the cooling efficiency of the cylinder head can be improved by effectively securing the flow rate of the cooling water from the cooling water introduction portion of the cylinder head to the inter-exhaust port flow path.

Brief description of the drawings

Fig. 1A is a schematic bottom view of a part of the cylinder head cooling structure of the first embodiment as viewed from below (cylinder block side).

Fig. 1B is a sectional view taken along line a-a of fig. 1A.

Fig. 2A is a schematic bottom view of a part of the cooling structure of the cylinder head according to the second embodiment, as viewed from below.

Fig. 2B is a sectional view taken along line a-a of fig. 2A.

Fig. 2C is a sectional view taken along line B-B of fig. 2A.

Fig. 3A is a schematic bottom view of a part of the cylinder head cooling structure according to the third embodiment, as viewed from below.

Fig. 3B is a sectional view taken along line a-a of fig. 3A.

Fig. 3C is a sectional view taken along line B-B of fig. 3A.

Fig. 4A is a schematic bottom view of a part of a cooling structure of a cylinder head according to another embodiment, as viewed from below (cylinder block side).

Fig. 4B is a sectional view taken along line a-a of fig. 4A.

Fig. 5A is a schematic bottom view of a part of a cooling structure of a cylinder head according to another embodiment, as viewed from below (cylinder block side).

Fig. 5B is a sectional view taken along line a-a of fig. 5A.

Fig. 6A is a schematic bottom view of a part of a cooling structure of a cylinder head according to another embodiment, as viewed from below (cylinder block side).

Fig. 6B is a sectional view taken along line a-a of fig. 6A.

Detailed Description

Hereinafter, a cooling structure of a cylinder head according to each embodiment of the present invention will be described with reference to the drawings.

[ first embodiment ]

Fig. 1A and 1B are diagrams illustrating a cooling structure of a cylinder head according to a first embodiment. The cooling structure of the present embodiment is applied to a multi-cylinder inline engine in which a plurality of cylinders are arranged in series in the longitudinal direction (crankshaft axis direction) of the engine.

A pair of

exhaust ports

12A, 12B and a pair of

intake ports

13A, 13B (shown only in fig. 1A) are disposed in opposed relation to each other with a gap therebetween in each of the cylinders 11A to 11C of the cylinder head 1, the pair of

exhaust ports

12A, 12B respectively accommodate two exhaust valves (not shown), and the pair of

intake ports

13A, 13B respectively accommodate two intake valves (not shown). Further, an injector boss portion 14 (only shown in fig. 1A) is provided between the

intake ports

13A and 13B facing between the

exhaust ports

12A and 12B, and the injector boss portion 14 is provided with an injector (not shown).

An exhaust-side head bolt boss portion 15 is provided between the cylinders 11A to 11C on the exhaust side of the cylinder head 1 with a space therebetween, and a head bolt not shown is inserted into the exhaust-side head bolt boss portion 15. Further, intake-side head bolt boss portions 16 (shown only in fig. 1A) are provided between the respective cylinders 11A to 11C on the intake side of the cylinder head 1 with a space therebetween, and the intake-side head bolt boss portions 16 are used for inserting head bolts (not shown).

On the intake side of the cylinder head 1, an intake side cooling water passage 20 (shown only in fig. 1A) is provided, and the intake side cooling water passage 20 extends in the longitudinal direction (hereinafter also referred to as the longitudinal direction) of the engine in the vicinity of the

intake ports

13A and 13B. A cooling water outlet (not shown) for returning the cooling water to a radiator (not shown) is provided at the downstream end of the intake side cooling water flow path 20.

On the exhaust side of the cylinder head 1, an exhaust port upper cooling water flow path 21 (shown only in fig. 1B) is provided, and the exhaust port upper cooling water flow path 21 extends in the longitudinal direction of the engine above the

exhaust ports

12A, 12B. The downstream side of the cooling water flow path 21 on the exhaust port is connected to the cooling water outlet (not shown).

An inter-cylinder cooling water flow path 23 is provided between the cylinders 11A to 11C of the cylinder head 1, and the inter-cylinder cooling water flow path 23 extends in the width direction of the engine. The inter-cylinder cooling water flow path 23 is formed by: the cooling

water flow paths

27A and 27B branch from the inner cylinder head bolt boss described in detail later, and the downstream ends thereof merge with the intake side cooling water flow path 20.

Between the

exhaust ports

12A, 12B and the

intake ports

13A, 13B of the cylinder head 1, there is provided an inter-intake/exhaust port cooling water flow path 24 (shown only in fig. 1A), and the inter-intake/exhaust port cooling water flow path 24 extends in the longitudinal direction substantially at the center of the engine and merges with the inter-cylinder cooling water flow path 23. The inter-intake/exhaust port cooling water flow path 24 is composed of a 1 st inter-intake/exhaust port cooling water flow path 24A and a 2 nd inter-intake/exhaust port cooling water flow path 24B, the 1 st inter-intake/exhaust port cooling water flow path 24A flows between the intake port 13A and the exhaust port 12A, and the 2 nd inter-intake/exhaust port cooling water flow path 24B flows between the intake port 13B and the exhaust port 12B.

A cooling water introduction portion 25 is provided below each of the

exhaust ports

12A and 12B of the cylinder head 1 in the longitudinal direction of the engine, and the cooling water introduction portion 25 is used to introduce cooling water into the cylinder head 1 from a water jacket of a cylinder block, not shown.

A 1 st inter-exhaust port cooling water flow path 26A is provided between the

exhaust ports

12A, 12B of the cylinder head 1, and the 1 st inter-exhaust port cooling water flow path 26A branches off from substantially the center in the longitudinal direction of the cooling water introduction portion 25 and extends between the

exhaust ports

12A, 12B, and the downstream end thereof merges with the inter-intake/exhaust port cooling water flow path 24 near the injector boss portion 14. Further, a 2 nd inter-exhaust port cooling water flow path 26B (shown only in fig. 1B) is provided above the 1 st inter-exhaust port cooling water flow path 26A, and the 2 nd inter-exhaust port cooling water flow path 26B extends upward from the 1 st inter-exhaust port cooling water flow path 26A and has its downstream end merged with the above-exhaust port cooling water flow path 21.

A pair of inside head bolt boss bypass cooling

water flow paths

27A, 27B are provided between the

exhaust ports

12A, 12B of the cylinder head 1 and the exhaust-side head bolt boss portion 15, and the pair of inside head bolt boss bypass cooling

water flow paths

27A, 27B are branched from both ends in the longitudinal direction of the cooling water introduction portion 25, extend inside the engine of the exhaust-side head bolt boss portion 15, and merge with the inter-cylinder cooling water flow path 23 and the exhaust-port upper cooling water flow path 21. The inside cylinder head bolt boss bypass cooling

water flow paths

27A and 27B are provided with

cutoff walls

70A and 70B, which will be described in detail later, respectively.

An outer cylinder head bolt boss bypass cooling water flow path 28 is provided on the engine outer side of the exhaust side cylinder head bolt boss portion 15, and the outer cylinder head bolt boss bypass cooling water flow path 28 extends in the longitudinal direction of the engine. In this way, the strength of the core used for casting is effectively ensured by connecting the cylinders by the cooling water flow path 28 beside the boss of the outer cylinder head bolt.

The

cutoff walls

70A, 70B are provided in the inside cylinder head bolt boss bypass cooling

water passages

27A, 27B so as to extend from the

exhaust ports

12A, 12B to the exhaust-side cylinder head bolt boss portion 15, and divide the merging portion of the inside cylinder head bolt boss bypass cooling

water passages

27A, 27B and the inter-cylinder cooling water passage 23. Namely, the structure is as follows: the flow of the cooling water to the cooling water introduction portion 25 → the inner head bolt boss side cooling

water flow paths

27A, 27B → the inter-cylinder cooling water flow path 23 → the inter-intake/exhaust port cooling water flow path 24 is cut off by the cutoff wall 70A, B, whereby the cooling water is forcibly caused to flow from the cooling water introduction portion 25 to the 1 st inter-exhaust port cooling water flow path 26A.

As described above in detail, according to the cooling structure of the first embodiment, the flow-blocking

walls

70A and 70B divide the joint portions with the inter-cylinder cooling water flow passage 23 in the inner cylinder head bolt boss side cooling

water flow passages

27A and 27B, so that the cooling water is easily flowed from the cooling water introduction portion 25 to the 1 st inter-exhaust port cooling water flow passage 26A, and the cooling efficiency of the cylinder head 1 can be effectively improved. Further, by providing the outside cylinder head bolt boss bypass cooling water flow path 28 extending in the longitudinal direction of the engine outside the exhaust side cylinder head bolt boss portion 15, the strength of the core used for casting the cylinder head 1 can be effectively ensured.

[ second embodiment ]

Fig. 2A to 2C are diagrams illustrating a cooling structure of a cylinder head according to a second embodiment. The same components as those of the first embodiment are denoted by the same reference numerals, and the names and functions thereof are also the same. Therefore, a detailed description thereof will be omitted.

The cooling structure of the second embodiment is configured such that: including the 1 st cutoff wall 71 (shown in fig. 2A and 2C) and the 2 nd cutoff wall 72 (shown in fig. 2B and 2C) provided in the inter-cylinder cooling water flow passage 23.

The 1 st blocking wall 71 is provided in the inter-cylinder cooling water flow path 23 so as to extend from the exhaust port 12B to the exhaust port 12A, the exhaust port 12B being located on the vertically upstream side (left side in fig. 2A) of the inter-cylinder cooling water flow path 23, and the exhaust port 12A being located on the vertically downstream side (right side in fig. 2A) of the inter-cylinder cooling water flow path 23. That is, the inter-cylinder cooling water flow path 23 leading from the cooling water introduction portion 25 to the inter-intake/exhaust port cooling water flow path 24 is divided by the 1 st cutoff wall 71.

The 2 nd blocking wall 72 is provided to extend from the exhaust port 12B to the exhaust port 12A (see also fig. 2B) in the vicinity of the junction with the above-exhaust-port cooling water flow path 21 in the inter-cylinder cooling water flow path 23, the exhaust port 12B being located on the vertical upstream side (left side in fig. 2A) with respect to the inter-cylinder cooling water flow path 23, and the exhaust port 12A being located on the vertical downstream side (right side in fig. 2A) with respect to the inter-cylinder cooling water flow path 23. That is, the inter-cylinder cooling water flow path 23 leading from the cooling water introduction portion 25 to the exhaust port upper cooling water flow path 21 is divided by the 2 nd cutoff wall 72.

As described above in detail, according to the cooling structure of the second embodiment, the flow of the cooling water from the cooling water introduction portion 25 to the inter-intake/exhaust port cooling water flow path 24 via the inter-cylinder cooling water flow path 23 is cut by the 1 st cutoff wall 71, and the flow of the cooling water from the cooling water introduction portion 25 to the on-exhaust port cooling water flow path 21 is cut by the 2 nd cutoff wall 72, whereby the amount of the cooling water from the cooling water introduction portion 25 to the 1 st inter-exhaust port cooling water flow path 26A can be effectively increased, and the cooling efficiency of the cylinder head 1 can be reliably improved.

[ third embodiment ]

Fig. 3A to 3C are diagrams illustrating a cooling structure of a cylinder head according to a third embodiment. The cooling structure of the third embodiment is configured to include: a transverse 3 rd cutoff wall 73 (shown in fig. 3B and 3C) that divides the 2 nd inter-exhaust port cooling water flow path 26B into a 1 st inter-exhaust port cooling water flow path 26A and a 2 nd inter-exhaust port cooling water flow path 26B connecting the above-exhaust port cooling water flow path 21; and a 4 th cutoff wall 74 in the up-down direction (shown in fig. 3A and 3C). By thus dividing the 2 nd inter-exhaust port cooling water flow path 26B by the 3 rd and 4

th blocking walls

73 and 74, the flow of the cooling water from the 1 st inter-exhaust port cooling water flow path 26A to the inter-intake/exhaust port cooling water flow path 24 is not obstructed, and the cooling efficiency of the cylinder head 1 can be effectively improved.

The present invention is not limited to the above embodiments, and can be implemented by being appropriately modified within a range not departing from the gist of the present invention.

For example, as shown in fig. 4, the second embodiment may be configured such that: the flow of the cooling water is completely shut off by providing the 1 st cutoff wall 71 extending to the upper surface side of the cylinder head 1 without providing the 2 nd cutoff wall 72. As shown in fig. 5, the present invention may be configured such that: a portion of the 1 st cutoff wall 71 or the 2 nd cutoff wall 72 is selectively omitted to change the flow of the cooling water or the like and secure the strength of the core.

As shown in fig. 6, the present invention may be configured such that: the flow

path throttling protrusions

30A and 30B protruding from the

exhaust ports

12A and 12B into the cooling water introduction portion 25 by a predetermined protruding amount are provided, so that the amount of cooling water flowing from the cooling water introduction portion 25 to the inner head bolt boss bypass cooling

water flow paths

27A and 27B can be adjusted or shut off. Although fig. 6 shows an example in which the flow

path throttling protrusions

30A and 30B are provided in the second embodiment, the present invention can also be applied to other embodiments such as the first embodiment and the third embodiment.

The outside cylinder head bolt boss bypass cooling water flow path 28 can be applied not only to the first embodiment but also to other embodiments such as the second embodiment and the third embodiment.

The present application is based on Japanese patent application (Japanese application 2015-194307) filed on 30.9.2015 and the content thereof is incorporated herein by reference.

Industrial applicability

The present invention has an effect of improving the cooling efficiency of the cylinder head, and is useful for a cooling structure of the cylinder head, and the like.

Description of the reference numerals

1 Cylinder head

11A-11C cylinder

12A, 12B exhaust port

13A and 13B air inlet

14 injector boss part

15 exhaust side cylinder head bolt boss part

16 air inlet side cylinder head bolt boss part

20 cooling water flow path on air inlet side

Cooling water flow path on 21 exhaust port

23-cylinder cooling water flow path

24 cooling water flow path between air inlet and air outlet

25 cooling water introduction part

26A cooling water flow path between 1 st exhaust ports

26B 2 nd inter-exhaust port cooling water flow path

27A, 27B inner side cylinder head bolt boss side cooling water flow path

Cooling water flow path beside bolt boss of 28 outer side cylinder cover

70 cutoff wall

71 No. 1 cutoff wall

72 nd 2 nd flow-breaking wall

73 3 rd flow breaking wall

74 th flow-breaking wall

Claims

1. A cooling structure of a cylinder head, wherein a plurality of cylinders are arranged in series in the longitudinal direction of an engine, a pair of intake ports and a pair of exhaust ports are arranged on the cylinders along the longitudinal direction of the engine, and a cylinder head bolt boss part is arranged on the exhaust side between the cylinders;

the cooling structure of the cylinder head includes:

a cooling water introduction part which is provided below the exhaust port and introduces cooling water supplied from the cylinder block side into the cylinder head,

a boss-side cooling water flow path which branches from the cooling water introduction part and extends in the vicinity of the engine inner side of the cylinder head bolt boss part,

an inter-cylinder cooling water flow path extending in the width direction of the engine between the plurality of cylinders and having an upstream end merging with the boss-side cooling water flow path,

a cooling water flow path between the first exhaust port and the second exhaust port, the cooling water flow path branching from the cooling water introduction part and extending between the pair of exhaust ports, and

a 1 st cutoff wall provided in the inter-cylinder cooling water flow path to cut off the flow of cooling water from the cooling water introduction part to the inter-cylinder cooling water flow path via the boss bypass cooling water flow path,

an inter-intake/exhaust port flow path extending in the longitudinal direction of the engine between the exhaust port and the intake port and merging with a downstream end of the 1 st inter-exhaust port cooling water flow path,

a 2 nd inter-exhaust-port cooling water flow path which branches upward from the 1 st inter-exhaust-port cooling water flow path and whose downstream end merges with the above-exhaust-port upper cooling water flow path, and

and a 3 rd cutoff wall that is provided in the 2 nd inter-exhaust-port cooling water flow path and cuts off the flow of cooling water from the cooling water introduction portion to the 2 nd inter-exhaust-port cooling water flow path through the 1 st inter-exhaust-port cooling water flow path.

2. The cooling structure of a cylinder head according to claim 1,

further comprising: an exhaust port upper cooling water flow path extending in the longitudinal direction of the engine above the exhaust port and merging with a downstream end of the boss side cooling water flow path, and

and a 2 nd cutoff wall that is provided in the inter-cylinder cooling water flow path and cuts off the flow of cooling water from the cooling water introduction portion to the cooling water flow path on the exhaust port via the boss bypass cooling water flow path.

3. The cooling structure of a cylinder head according to claim 1,

the engine further includes an outer boss bypass cooling water passage that branches from the cooling water introduction portion and extends in the longitudinal direction of the engine on the engine outer side of the cylinder head bolt boss portion.

4. The cooling structure of a cylinder head according to any one of claims 1 to 3,

the cooling water supply device further includes a protrusion portion provided to protrude into the cooling water introduction portion by a predetermined protruding amount, and throttling a flow path of the cooling water from the cooling water introduction portion to the boss bypass cooling water flow path.