JPH025059Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention relates to a variable cylinder number engine, and more specifically, a variable cylinder number engine in which a shutoff valve is provided in the cooling water piping system connected to a group of cylinders that can be deactivated. It is related to the engine.

[Prior art]

In conventional multi-cylinder engines, the operation of specific cylinders is stopped when the engine is running at low speed and under light load to reduce the number of operating cylinders, thereby improving fuel efficiency in the light load range.

Most of these variable cylinder number engines have two cylinders that can be deactivated if the engine has four cylinders, and three cylinders that can be deactivated if the engine has six cylinders. V type 10
In the case of cylinders, the number of cylinders is changed in two stages, with half of all cylinders set as cylinders that can be deactivated, such as one bank (5 cylinders) being deactivable cylinders.

By the way, in the conventional variable cylinder number engine as described above, the cooling water piping systems connected to the activated cylinders and the deactivated cylinders meet at the engine outlet or the water pump inlet. For this reason, the cooling water circulates uniformly to all cylinders,
During reduced-cylinder operation, the temperature of the cooling water at the engine outlet of the cylinder group that can be stopped is low, and the temperature of the cooling water of the active cylinder group is high.

As a result, the cooling water that has circulated through the active cylinder group up to the inlet of the water pump and the cooling water that has circulated through the deactivable cylinder group merge, resulting in a lower water temperature.
For this reason, when using the above-mentioned combined coolant whose temperature has decreased by guiding it to a heater for heating the passenger compartment,
Because the water temperature is low, the effectiveness of the heater becomes poor, especially when keeping warm inside the vehicle when the vehicle is stopped in the winter.
There was a problem that the heater was not effective when operating with a reduced number of cylinders to improve fuel efficiency.

[Purpose of invention]

This idea was devised by focusing on the conventional problems, and its purpose is to make the heater have the same warming effect during reduced-cylinder operation as in full-cylinder operation. This provides an engine with a variable number of cylinders.

[Structure of the idea]

The configuration of the variable multi-cylinder engine of this invention to achieve the above object is that a first cooling water passage for cooling a group of cylinders that is constantly operated is attached to the water pump, and the water pump is operated in parallel with the first cooling water passage. It is characterized by the installation of a second cooling water passage with a shutoff valve that cools the stoppable cylinders.

The shutoff valve can be operated in conjunction with a normal cylinder reduction operation switch, or in conjunction with temperature detection means for detecting the temperature of a group of cylinders that can be deactivated.

Since the shutoff valve allows cooling water to flow only to the operating engine side during cylinder reduction, it is possible to prevent the temperature of the cooling water flowing out from the engine from decreasing.

〔Example〕

Embodiments of this invention will be described below based on the accompanying drawings.

FIG. 1 shows a schematic configuration diagram in which this invention is applied to a variable cylinder number V-type engine, and this engine 1 has the following features:
An active cylinder group 2 consisting of a plurality of actuating cylinders and a deactivatable cylinder group 3 consisting of a plurality of deactivatable cylinders.
It is equipped with

The active cylinder group 2 and the deactivable cylinder group 3 include inflow pipes 4a, 4b and outflow pipes 5a, 5a, 4b for the cooling water W,
A cooling water piping system consisting of the inflow pipes 4a, 4b and the outflow pipes 5a, 5b are connected to each other independently.
The gathering parts 4 and 5 with 5b are connected to the inlet and outlet of the radiator 6. In the embodiment shown in FIG. 1, the first cooling water passage of the present invention is constituted by a cooling water passage (not shown) provided in the operating cylinder group 2, an inflow pipe 4a, and an outflow pipe 5a, and A cooling water passage (not shown), an inflow pipe 4b, and an outflow pipe 5 provided in the
b respectively constitute the second cooling water passage of the present invention.

A water pump 7 is provided at the gathering portion 4 of the cooling water W inflow pipes 4a, 4b, and a thermostat 8 is provided upstream thereof. Cooling water W connecting water pump 7 and operating cylinder group 2
A supply pipe 10a for circulating heated cooling water W to the heater 9 is connected to the inlet pipe 4a and the collecting part 4 that connects the water pump 7 and the radiator 6.
and a discharge pipe 10b are provided.

Further, a cutoff valve 11 is installed in the outflow pipe 5b of the cooling water W connected to the cylinder group 3 that can be deactivated, which detects the temperature of the cooling water W and shuts off the flow of the outflow pipe 5b. This cutoff valve 11 is equipped with a temperature detection means (not shown), and when the temperature of the cooling water W in the cylinder group 3 that can be stopped during cylinder reduction operation falls below a set value, the cutoff valve 11 is closed to cool the water at a low temperature. This prevents water from flowing into the collecting section 4 on the upstream side of the water pump 7.

Note that 12 indicates inflow pipes 4a, 4b and outflow pipe 5a,
5b.

Next, the effect will be explained.

First, during normal operation when the shutoff valve 11 is open, the cooling water W flowing out from the radiator 6 passes through the thermostat 8 as shown by the arrow and enters the collection part 4 of the water pump 7, and then flows into the inlet pipe branched from there. 4a and 4b, it uniformly flows into the active cylinder group 2 and the deactivable cylinder group 3. Operating cylinder group 2
The cooling water W that entered the cylinder group 3 that can be deactivated is
The heated cooling water W1 is heated by the combustion heat of the engine 1, engine friction, etc., and is recycled to the radiator 6 through the outflow pipes 5a and 5b.

On the other hand, a part of the heated cooling water W1 is supplied to the heater 9 through the supply pipe 10a connected to the inflow pipe 4a, where it undergoes heat exchange, and then passes through the discharge pipe 10b to the inflow pipe. It flows into the gathering part 4.

Next, during reduced cylinder operation, cylinder group 3 that can be deactivated
The cutoff valve 11 of the outflow pipe 5b connected to the outflow pipe 5b closes when the water temperature detection means detects the set temperature in the cylinder group 3 that can be deactivated. Therefore, the cooling water W circulating inside the engine 1 is only on the active cylinder group 2 side,
As the temperature of the cooling water W becomes higher, the water flow also becomes faster.

On the other hand, the cooling water in the cylinder group 3 that can be deactivated is in a stagnant state. Therefore, since the heated cooling water W1 and the cooling water W having a low water temperature do not join together, the temperature of the cooling water W1 is less likely to drop, and the heated cooling water W1 flowing into the heater 9 is prevented by the same operation as described above. The amount of cooling water W1 increases, the temperature also increases, and the efficiency of heat radiation from the heater 9 also improves.

Note that the operation of the cutoff valve 11 may be linked to a switch or the like that is operated during reduced cylinder operation of the engine 1, and by doing so, the cutoff valve 11 can be opened and closed with good response.

Next, Figure 2 shows this idea in an in-line engine 1.
This shows another embodiment applied to a (6 cylinders). In the case of this embodiment, the front three cylinders are the active cylinders 2a, and the rear three cylinders are the deactivated cylinders 3a.
A partition wall 13 is provided inside the engine 1a, and a shutoff valve similar to that of the first embodiment is provided at the boundary gathering portion 14 of the cooling water W outflow pipes 14a, 14b connected to the active cylinder 2a and the deactivable cylinder 3a. 21 was inserted. The embodiment shown in FIG.
4a constitutes the first cooling water passage of the present invention, and the unillustrated cooling water passage provided in the inactive cylinder group 3 and the outflow pipe 14b constitute the second cooling water passage of the present invention. ing.

The shutoff valve 21 is closed during reduced cylinder operation to circulate only the heated cooling water W1 from the active cylinder 2a to the heater 9.

Regarding other configurations and effects,
Since it is similar to the first embodiment described above, the same reference numerals are given and the explanation will be omitted.

[Effect of idea]

As mentioned above, this idea includes a cutoff valve in the cooling water piping system connected to the cylinder group that can be deactivated in a variable cylinder number engine, so that the heat dissipated from the heater during reduced cylinder operation is the same as when all cylinders are operating. The heating effect of the heater is particularly good when warming the vehicle while the vehicle is stopped during winter, and at the same time, it has the effect of improving fuel efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a V-type variable cylinder number engine implementing this invention, and FIG. 2 is a schematic diagram of an in-line variable cylinder number engine showing another embodiment. 1...Variable cylinder number engine, 2...Activated cylinder group, 3...Cylinders that can be deactivated, 4a, 4b...Inflow pipe (cooling water piping system), 5a, 5b...Outflow pipe (cooling water piping system) , 11...Shutoff valve.

Claims (1)

[Claims for Utility Model Registration] 1. A water pump is equipped with a first cooling water passage that cools a group of cylinders that are constantly in operation, and is equipped with a shutoff valve that cools a cylinder group that can be stopped in operation in parallel with the first cooling water passage. Variable multi-cylinder engine equipped with a second cooling water passage. 2. The variable cylinder number engine according to claim 1, wherein the cutoff valve is linked to a cylinder reduction operation switch. 3. The variable cylinder number engine according to claim 1, wherein the cutoff valve is provided with temperature detection means for detecting the temperature of the cylinder group that can be deactivated.