Gas engine

Patent metadata

Field	Value
Publication number	US-10690062-B2
Application number	US-201515314704-A
Country	US
Kind code	B2
Filing date	Apr 20, 2015
Priority date	May 30, 2014
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

While providing the control such that the air excess ratio falls within the stoichiometric range, if the throttle opening degree control means determines that a value of the torque is smaller than A [Nm], the throttle opening degree control means provides a first control of controlling the opening degree of the intake throttle valve such that the output shaft rotates at a constant first rotation number. If the throttle opening degree control means determines that the value of the torque is larger than A [Nm], the throttle opening degree control means provides a second control of controlling the opening degree of the intake throttle valve such that the rotation number of the output shaft becomes larger.

First claim

The invention claimed is:

1. A gas engine comprising:
a mixer configured to mix an air and a fuel to generate an air-fuel mixture;
a cylinder head comprising an intake port configured to receive the air-fuel mixture from the mixer;
an intake throttle valve configured to adjust a flow-rate of the air-fuel mixture from the mixer to the intake port;
a torque calculating means for calculating a torque value associated with an output shaft;
an excess ratio identifying means for identifying an air excess ratio of the air-fuel mixture;
an excess ratio adjusting means for adjusting the air excess ratio;
a throttle opening degree control means for controlling an opening degree of the intake throttle valve based on a signal indicative of the torque value from the torque calculating means; and
an excess ratio control means for controlling the excess ratio adjusting means such that the air excess ratio is within a stoichiometric range,
wherein, while the air excess ratio is controlled by the excess ratio control means to be within the stoichiometric range:
if the throttle opening degree control means determines that the torque value is less than a first predetermined value, the throttle opening degree control means is configured to control the opening degree of the intake throttle valve such that the output shaft rotates at a constant first rotation number, or
if the throttle opening degree control means determines that the torque value is greater than the first predetermined value, the throttle opening degree control means is configured to control the opening degree of the intake throttle valve such that a rotation number of the output shaft increases.

2. The gas engine according to claim 1 , wherein if the throttle opening degree control means determines that the torque value is greater than the first predetermined value, the throttle opening degree control means is configured to control the opening degree of the intake throttle valve such that the rotation number increases in accordance with a linear function the torque value to be greater than the first predetermined value.

3. The gas engine according to claim 1 , further comprising:
a cooling water temperature sensor configured to detect a temperature of a cooling water and to output a signal indicative of the temperature of the cooling water to the throttle opening degree control means,
wherein, when the temperature of the cooling water is less than a second predetermined value, the throttle opening degree control means is configured to control the opening degree of the intake throttle valve such that the output shaft rotates at a constant second rotation number.

4. The gas engine according to claim 3 , wherein the cooling water is provided to suppress overheating due to combustion of the air-fuel mixture in a combustion chamber.

5. The gas engine according to claim 1 , wherein:
when a temperature of cooling water is greater than a second predetermined value, the throttle opening degree control means is configured to:
perform a comparison between the torque value and the a first predetermined value; and
control the opening degree of the intake throttle valve based on a result of the comparison.

6. A system comprising:
a controller associated with an engine, the controller configured to, while an air excess ratio is controlled to be within a stoichiometric range:
when a temperature of cooling water associated with the engine is greater than a predetermined temperature value:
perform a comparison between a torque value associated with an output shaft and a first predetermined value; and
initiate control of an opening degree of an intake throttle valve based on a result of the comparison
wherein, in response to the result of the comparison indicating that the torque value is less than a first predetermined value, the opening degree of the intake throttle valve is controlled such that the output shaft rotates at a constant first rotation number.

7. The system of claim 6 , wherein, when the result of the comparison indicates that the torque value is greater than the first predetermined value, the opening degree of the intake throttle valve is controlled such that a rotation number of the output shaft increases.

8. The system of claim 6 , wherein the controller is further configured to, while an air excess ratio is controlled to be within a stoichiometric range:
when the temperature of the cooling water is less than a predetermined temperature value, initiate control the opening degree of the intake throttle valve such that the output shaft rotates at a constant second rotation number.

9. The system of claim 6 , further comprising:
the engine coupled to the controller.

10. A system comprising:
a controller associated with an engine, the controller configured to, while an air excess ratio is controlled to be within a stoichiometric range:
when a temperature of cooling water associated with the engine is greater than a predetermined temperature value:
perform a comparison between a torque value associated with an output shaft and a first predetermined value; and
initiate control of an opening degree of an intake throttle valve based on a result of the comparison
wherein, in response to the result of the comparison indicating that the torque value is greater than a first predetermined value, the opening degree of the intake throttle valve is controlled such that a rotation number of the output shaft increases.

11. The system of claim 10 , wherein the controller is further configured to, while an air excess ratio is controlled to be within a stoichiometric range:
when the temperature of the cooling water is less than a predetermined temperature value, initiate control the opening degree of the intake throttle valve such that the output shaft rotates at a constant second rotation number.

12. The system of claim 10 , further comprising:
the engine coupled to the controller.

Assignees

• Yanmar Co Ltd

Inventors

• Hidaka Hiromitsu

Classifications

• F02D19/02 Primary

  peculiar to engines working with gaseous fuels · CPC title

• F02D31/002

  controlling air supply · CPC title

• Y02T10/30

  Use of alternative fuels, e.g. biofuels · CPC title

• F02D31/007

  controlling fuel supply · CPC title

• F02D41/0027

  the fuel being gaseous (non-electrical control F02D19/02) · CPC title