Flow rate and flow velocity measurement device

• US 6,526,822 B1
• Filed: 10/06/2000
• Issued: 03/04/2003
• Est. Priority Date: 10/06/1999
• Status: Expired due to Fees

• Current Assignee: NGK Spark PLUG Company Limited
• Original Assignee: NGK Spark PLUG Company Limited
• Inventors: Maeda, Shunsuke, Suda, Masanori, Kuzuya, Yasuhisa, Kohmura, Yoshihiko, Kojima, Takio, Oshima, Takafumi
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): Martir, Lilybett
• Application Number:
  US09/679,565
• Time in Patent Office: 879 Days
• Field of Search: 732/025, 732/042.1, 732/022.2, 732/041.2, 732/041.1
• US Class Current: 73/204.21
• CPC Class Codes: G01F 1/6842 with means for influencing the fluid flow

Abstract

A flow measurement device is disclosed, in which an accumulation of pollution substance onto a detection element is prevented, and which can measure a reverse flow similarly to a normal flow. On both ends of an outer wall 23 outer peripheral portion of a divided flow pipe 20 having a Ω-shape pipe passage, there are oppositely formed an inlet port 25 and an outlet port 26, which open in faces orthogonal to a flow direction of a main flow M that is a detection object. Within the divided flow pipe 20, by a curved partition 27, plural branch flow passages 28a, 28b mutually branching and joining in the divided flow pipe 20 are formed. Inside both end portions of the outer wall 23, undulation portions 32, 33 are formed so as to clog an inlet and an outlet of the outer peripheral side branch flow passage 28a and, by this, throttles are formed respectively in a flow passage between the inlet port 25 and the inlet of the branch flow passage 28a and a flow passage between the outlet port 26 and the outlet of the branch flow passage 28a. In a bottom portion of the outer wall 23 of the divided flow pipe 20, a detection element 31 is attached so as to be exposed to a flow in the outer peripheral side branch flow passage 28a and, against its detection face, a down flow DW further divided from a divided flow D obliquely impinges.

Claims

1. A flow measurement device comprising:

a divided flow pipe which has a divided flow pipe passage in a curved, substantially Ω

-shape form, and into which at least a portion of a flow in a main flow pipe, which flow is the object of the measurement, is to be introduced;

an inlet plate forming the curved divided flow pipe passage provided in the divided flow pipe;

a partition formed in the divided flow pipe;

plural branch flow passages defined by and arranged on opposite sides of the partition so as to mutually branch and join in the divided flow pipe; and

a detection element which is disposed so as to be exposed to a flow in one of said plural branch flow passages, for detecting a quantity concerning the flow.

2. The flow measurement device as claimed in claim 1, further comprising:

an inlet port of the divided flow pipe, which is formed in an outer peripheral side of the divided flow pipe passage, and which opens in a face arranged to be approximately orthogonal to a flow direction in the main flow pipe,

and wherein said detection element is disposed so as to be exposed to a flow in the branch flow passage formed in the outer peripheral side of the divided flow pipe.

3. The flow measurement device as claimed in claim 2, further characterized in that the inlet port of the divided flow pipe and an inlet of the outer peripheral side branch flow passage in which the detection element is disposed are opened in substantially mutually orthogonal faces, and the flow introduced into the divided flow pipe is changed in its direction and flows into the branch flow passage.

4. The flow measurement device as claimed in claim 2, further characterized in that:

an end portion of the partition is above the inlet port of the divided flow pipe; and

an inlet of at least the outer peripheral side branch flow passage opens above the inlet port of the divided flow pipe.

5. The flow measurement device as claimed in claim 2, further characterized in that a throttle is formed in a flow passage between the inlet port of the divided flow pipe and an inlet of a said branch flow passage.

6. The flow measurement device as claimed in claim 5, further characterized in that:

the throttle is defined by at least one undulation portion formed in either one or more of;

an outer wall inside of the divided flow pipe;

the partition;

aid the inlet plate.

7. The flow measurement device as claimed in claim 6, further characterized in that the undulation portion protrudes from the outer wall inside of the divided flow pipe or from the inlet plate, in the vicinity of said inlet of said branch flow passage, and that the apex of the undulation portion protrudes at least as far as the level of the partition.

8. The flow measurement device as claimed in claim 1, further characterized in that:

an inlet plate forming the curved divided flow pipe passage is provided in the divided flow pipe; and

below the inlet port of the divided flow pipe, an inner peripheral side flow passage wall forming the divided flow pipe passage undulates and a flow passage face of concave curved face form is formed.

9. The flow measurement device as claimed in claim 1, further characterized in that the divided flow pipe has a flow passage structure substantially symmetrical with respect to the detection element.

10. The flow measurement device as claimed in claim 1, further characterized in that a throttle is formed in a flow passage between an outlet port of the divided flow pipe and an outlet of a branch flow passage.

11. The flow measurement device as claimed in claim 10, further characterized in that:

an inlet plate forming the curved divided flow pipe passage is provided in the divided flow pipe; and

the throttle is defined by at least one undulation portion formed in either one or more of;

an outer wall inside of the divided flow pipe;

the partition; and

the inlet plate.

12. The flow measurement device as claimed in claim 11, further characterized in that the undulation portion protrudes from the outer wall inside of the divided flow pipe or from the inlet plate, in the vicinity of the outlet of said branch flow passage, and that the apex of the undulation portion protrudes at least as far as the level of the partition.

13. The flow measurement device as claimed in claim 2, further characterized in that:

in an outer peripheral side of the divided flow pipe passage, an outlet port of the divided flow pipe is formed so as to open in a face approximately orthogonal to the flow direction in the main flow pipe, while being opposed to the inlet port of the divided flow pipe;

an inlet plate forming the curved divided flow pipe passage is provided in the divided flow pipe; and

a bypass flow passage short-circuiting between the inlet port and the outlet port of the divided flow pipe is formed between one end of the inlet plate and a top outer wall of the divided flow pipe.

14. The flow measurement device as claimed in claim 13, further characterized in that:

an orifice is provided in the bypass flow passage; and

a flow rate of a measurement fluid toward the detection element is set by a protrusion amount of a flow passage wall forming the orifice or by the orifice open area.

15. The flow measurement device as claimed in claim 14, further characterized in that the flow passage wall forming the orifice is protruded toward an orifice center, and a sectional shape of a flow passage face of the protruded portion is any one of a polygonal face, a curved face and a duplex curved face.

16. The flow measurement device as claimed in claim 1, further characterized by having flow control means provided in the branch flow passage in which the detection element is disposed and forming such a flow as obliquely impinges against a detection face of the detection element.

17. The flow measurement device as claimed in claim 1, further characterized in that, on a wall face of the partition opposite to the detection element, a Venturi is provided from upstream to downstream of the detection element, and a flow passage of the branch flow passage in which the detection element is disposed is made narrowest in the vicinity of a center of the of the detection element by the Venturi.

18. The flow measurement device claimed in claim 1,

wherein said detection element is disposed so as to be exposed to a flow in a branch flow passage formed in an inner peripheral side or an intermediate portion of the divided flow pipe;

and

further comprising a throttle formed in a flow passage between an inlet port of the divided flow pipe and an inlet of the branch flow passage in which a detection face of the detection element is exposed to the flow therein.

19. The flow measurement device as claimed in claim 18, further characterized in that the detection element is provided in the partition.

20. The flow measurement device as claimed in claim 1, further comprising:

an inlet port of the divided flow pipe, which is formed in one end outer peripheral side of the divided flow pipe passage, and which opens in a face arranged to he approximately orthogonal to a flow direction in the main flow pipe; and

an outlet port of the divided flow pipe, which is formed in the other end top of the divided flow pipe passage, and opens in a face approximately parallel to a flow direction in the main flow pipe,

wherein said partition formed in the divided flow pipe, has one end which extends to a vicinity of the inlet port, and has another end which extends while being spaced from the outlet port; and

wherein said detection element is disposed so as to be exposed to a flow in the branch flow passage formed in an outer peripheral side of the divided flow pipe.

21. The flow measurement device as claimed in claim 20, further characterized in that:

an inlet plate forming the curved divided flow pipe passage is provided in the divided flow pipe; and

in the vicinity of the inlet port of the divided flow pipe, at least one undulation portion is formed in either one or more of;

an outer wall inside of the divided flow pipe;

the partition; and

the inlet plate, and by the or each undulation portion a throttle is formed in a flow passage between the inlet port of the divided flow pipe and an inlet of the outer peripheral side branch flow passage.

22. The flow measurement device as claimed in claim 1, further comprising:

an inlet port of the divided flow pipe and an inlet of the branch flow passage, which are mutually formed such that the flow introduced into the divided flow pipe is changed in its direction when flowing into the branch flow passage in which the detection element is exposed to the flow therein.

23. The flow measurement device as claimed in claim 1, further comprising:

a throttle formed in a flow passage between an inlet port of the divided flow pipe and an inlet of the branch flow passage such that the flow introduced into the divided flow pipe is changed in its direction when flowing into the branch flow passage in which the detection element is exposed to the flow therein.

24. The flow measurement device as claimed in claim 1, further comprising:

an inlet port of the divided flow pipe, which is formed in one end outer peripheral side of the divided flow pipe passage, and which opens in a face arranged to be approximately orthogonal to a flow direction in the main flow pipe;

an outlet port of the divided flow pipe, which is formed in the other end outer peripheral side of the divided flow pipe passage, and which opens in a face arranged to be approximately orthogonal to a flow direction in the main flow pipe;

throttles formed respectively in a flow passage between the inlet port of the divided flow pipe and an inlet of the outer peripheral side branch flow passage and a flow passage between the outlet port of the divided flow pipe and an outlet of the outer peripheral side branch flow passage, wherein said detection element is disposed so as to be exposed to a flow in the branch flow passage formed in an outer peripheral side of the divided flow pipe; and

a Venturi provided, on a wall face of the partition opposite to the detection element and from an upstream to a downstream of the detection element, such that a flow passage of the branch flow passage in which the detection element is disposed is made narrowest in the vicinity of a center of the detection element.

25. The flow measurement device as claimed in claim 1, for installation in an intake system of an internal combustion engine mounted on a vehicle.