Valve and method for producing a valve

Patent metadata

Field	Value
Publication number	US-11060494-B2
Application number	US-201916531941-A
Country	US
Kind code	B2
Filing date	Aug 5, 2019
Priority date	Sep 2, 2014
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A valve is provided, in particular an injection valve, having a valve seat and a valve needle which extends along a closing direction for the most part, the valve seat having a valve-seat surface, and a valve-closing element is mounted on an end of the valve needle facing the valve seat, the valve-closing element being able to be moved between an open position and a closed position, and the valve-closing element together with the valve-seat surface forming a sealing seat in the closed position, the valve-closing element having a greater core hardness and/or surface hardness than the valve-seat surface.

First claim

What is claimed is:

1. An injection valve, comprising:
a valve seat having a valve-seat surface; and
a valve needle which extends along a closing direction, a valve-closing element being mounted on an end of the valve needle facing the valve seat, the valve-closing element being able to be moved between an open position and a closed position, the valve-closing element forming a sealing seat together with the valve-seat surface in the closed position;
wherein the valve-closing element has at least one of: i) a greater core hardness than the valve-seat surface, or ii) a greater surface hardness than the valve-seat surface; and
wherein the valve-closing element includes a base body material and at least one diffusion layer with nitrogen and boron diffused into the base body material, the at least one diffusion layer being produced by (i) conducting a nitrifying diffusion on the valve-closing element, the nitrifying diffusion including diffusing nitrogen into the base body material by providing a nitrogen-containing substance in at least one of: a gaseous state, a liquid state, or a plasma state; and (ii) conducting a boronizing diffusion on the valve-closing element, the boronizing diffusion including diffusing boron into the base body material by providing a boron-containing substance in at least one of: a gaseous state, a liquid state, or a plasma state.

2. The valve as recited in claim 1 , wherein the valve-seat surface is adapted to a form of the valve-closing element, and the valve-closing element has a spherical form.

3. The valve as recited in claim 1 , wherein the valve-closing element has a surface region and in the closed position, the valve-closing element is in contact with the valve-seat surface in the surface region, the valve-closing element having a greater surface hardness in the surface region than the valve-seat surface.

4. The valve as recited in claim 3 , wherein the surface region of the valve-closing element includes the diffusion layer, and the diffusion layer has a greater surface hardness than the valve-seat surface.

5. The valve as recited in claim 3 , wherein the surface region includes a layer made of a coating material, the layer having a greater surface hardness than the valve-seat surface, the layer being an amorphous carbon layer.

6. The valve as recited in claim 5 , wherein a surface of the valve-closing element is at least partially made up of the layer.

7. The valve as recited in claim 5 , wherein the layer has a coating thickness between 0 and 50 micrometers.

8. The valve as recited in claim 5 , wherein the layer has a coating thickness between 1 and 20 micrometers.

9. The valve as recited in claim 5 , wherein the layer has a coating thickness between 1.5 and 5 micrometers.

10. The valve as recited in claim 1 , wherein the valve-closing element includes a body formed from the base body material.

11. The valve as recited in claim 1 , wherein a center of the valve-closing element is formed from the base body material.

12. The valve as recited in claim 1 , wherein the nitrogen is diffused into the base body material in the at least one diffusion layer to a depth of between 1 and 100 micrometers.

13. The valve as recited in claim 1 , wherein the nitrogen is diffused into the base body material in the at least one diffusion layer to a depth of between 5 and 50 micrometers.

14. The valve as recited in claim 1 , wherein the nitrogen is diffused into the base body material in the at least one diffusion layer to a depth of between 10 and 20 micrometers.

15. The valve as recited in claim 1 , wherein the boron is diffused into the base body material in the at least one diffusion layer to a depth of between 1 and 100 micrometers.

16. The valve as recited in claim 1 , wherein the boron is diffused into the base body material in the at least one diffusion layer to a depth of between 5 and 90 micrometers.

17. The valve as recited in claim 1 , wherein the nitrogen is diffused into the base body material in the at least one diffusion layer to a depth of between 15 and 30 micrometers.

Assignees

• Bosch Gmbh Robert

Inventors

• Mutlu Fatima

Classifications

• C23C8/06

  using gases (C23C8/36 takes precedence) · CPC title

• C23C8/40

  using liquids, e.g. salt baths, liquid suspensions · CPC title

• C23C8/24

  Nitriding · CPC title

• F02M61/10

  Other injectors with elongated valve bodies, i.e. of needle-valve type · CPC title

• C23C8/30

  Carbo-nitriding · CPC title